JavaScript - Check If A Select Value Exists?

Can I do something like the below to see if a form exists in a document.

Code:

if(document.theForm){
alert('form exists');

}

Greetings,

If I have a form like so:
Code:

<form>
  <input type="text" />
</form>

How can I check if the input exists using DOM 0?

Code:

while (document.forms[0].elements[0].exists){
 ...do something
}

I guess that I could assign a default value and check for something in
"document.forms[0].elements[0].value" but that is not the approach I wish to take.

I need to loop through all of the elements of a form until there are no more regardless of ID/name/value, am I thinking about this wrong?

is there a way to do this with javascript ?

Code:

var fID = document.getElementById('email2');

I'm making a table that is dynamically populated from XML data. One of the columns refers to an XML tag that is NOT required (hence the tag does not exist in every XML entry). How do I write a statement (if, else, or any other?) that says - check for the tag, if the tag exists, write the tag's data, if the tag does NOT exist, write "n/a".

Here's the code:

Thanks!

[CODE]
<script type="text/javascript">
if (window.XMLHttpRequest)
{
xhttp=new window.XMLHttpRequest();
}
else // Internet Explorer 5/6
{
xhttp=new ActiveXObject("Microsoft.XMLHTTP");
}




xhttp.open("GET","http://www.mysite.com/file.xml",false);
xhttp.send("");
xmlDoc=xhttp.responseXML;


document.write("<table border='0' style='font-family:Arial, Helvetica, sans-serif; font-size:11px; color:#333333; border:#333333 1px solid; text-align:center' cellpadding='5' cellspacing='0'>");
document.write("<tr><td style='border-bottom:#333333 1px solid'><strong>Type</strong></td><td style='border-bottom:#333333 1px solid'><strong>Name</strong></td><td style='border-bottom:#333333 1px solid'><strong>Details</strong></td><td style='border-bottom:#333333 1px solid'><strong>Code<br>(if applicable)</strong></td><td style='border-bottom:#333333 1px solid'><strong>Start Date</strong></td><td style='border-bottom:#333333 1px solid'><strong>End Date</strong></td></tr>");



var x=xmlDoc.getElementsByTagName("link");
for (i=0;i<x.length;i++)
{
document.write("<tr><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("type")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("name")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("description")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("code")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("startdate")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("enddate")[0].childNodes[0].nodeValue);
document.write("</td></tr>");
}
document.write("</table>");
</script>
[CODE]

Thanks,
M8AL

I'm making a table that is dynamically populated from XML data. One of the columns refers to an XML tag that is NOT required (hence the tag does not exist in every XML entry). How do I write a statement (if, else, or any other?) that says - check for the tag, if the tag exists, write the tag's data, if the tag does NOT exist, write "n/a".

Here's the code:

[CODE]
<script type="text/javascript">
if (window.XMLHttpRequest)
{
xhttp=new window.XMLHttpRequest();
}
else // Internet Explorer 5/6
{
xhttp=new ActiveXObject("Microsoft.XMLHTTP");
}




xhttp.open("GET","http://www.mysite.com/file.xml",false);
xhttp.send("");
xmlDoc=xhttp.responseXML;


document.write("<table border='0' style='font-family:Arial, Helvetica, sans-serif; font-size:11px; color:#333333; border:#333333 1px solid; text-align:center' cellpadding='5' cellspacing='0'>");
document.write("<tr><td style='border-bottom:#333333 1px solid'><strong>Type</strong></td><td style='border-bottom:#333333 1px solid'><strong>Name</strong></td><td style='border-bottom:#333333 1px solid'><strong>Details</strong></td><td style='border-bottom:#333333 1px solid'><strong>Code<br>(if applicable)</strong></td><td style='border-bottom:#333333 1px solid'><strong>Start Date</strong></td><td style='border-bottom:#333333 1px solid'><strong>End Date</strong></td></tr>");



var x=xmlDoc.getElementsByTagName("link");
for (i=0;i<x.length;i++)
{
document.write("<tr><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("type")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("name")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("description")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("code")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("startdate")[0].childNodes[0].nodeValue);
document.write("</td><td style='border-bottom:#333333 1px solid'>");
document.write(x[i].getElementsByTagName("enddate")[0].childNodes[0].nodeValue);
document.write("</td></tr>");
}
document.write("</table>");
</script>
[CODE]

Thanks,
M8AL

Hi All,

I am not an expert in Javascript.

Can I detect if 1 or more sessions of a website are open?

for example, if a session with port 7005 is open like this one below, then I want to assign the next port to this user in the second window of browser

http://90.97.8.0:7005/maximo/webclient/login/login.jsp

the next IE window should appear like this:

http://90.97.8.0:7006/maximo/webclient/login/login.jsp

or
http://90.97.8.0:7007/maximo/webclient/login/login.jsp

Please advise.

Thanks

Yasar

On this webpage
http://www.corkdiscos.com/testimonials.html

i have a like button.
when a user clicks like a comment box appears.
when i unlike the button the comment box disappears

this is ok but when a user has already liked the facebook page and comes to my webpage
the comment box does not show.

so im looking for a piece of javascript to check if a user has like the button on my page and if so to show the comment box.

please check my source code of the website http://www.corkdiscos.com/testimonials.html to see what i have so far.

any help would be greatly appreciated

Hi guys.

I'm working a bunch of pre existing code on a CMS. Just after a quick fix. Doing a show/hide thing on a particular div somewhere on the page depending if a checkbox is ticked or not.

Currently there is 3 checkboxes that are dynamically added through the CMS.

Here's simplified version of the form:

Code:

<form id="simplesearch" name="simplesearch">
<input type="checkbox"   onclick='showhidefield(this.value)' name="meta_data_array_search_criteria[custom_profile_type][]" value="5"  class="input-checkboxes" />
<input type="checkbox"   onclick='showhidefield(this.value)' name="meta_data_array_search_criteria[custom_profile_type][]" value="4"  class="input-checkboxes" />
</form>

And here's the javascript I was playing with.
Code:

function showhidefield(id)
{
   if(document.simplesearch.meta_data_array_search_criteria[custom_profile_type][''].checked) {
      document.getElementById("profile_fields_wrapper_" + id).style.visibility = "visible";
   }
   else
   {
      document.getElementById("profile_fields_wrapper_" + id).style.visibility = "hidden";
   }
}

Problem I'm having is how do i do a check to see if those checkboxes are checked in the javascript with those name arrays? How do i separate them? 'm guessing I have to loop through them or something?Hopefully that make senses - it's late here and I'm losing the plot Any pointers would be gratefully welcomed

I've been having problems getting my select option to change the options of another select option. I'm not much of a javacsript coder, so I'm at a lost.

When I select the first option nothing appears in the second option.

here's the javascript code:

Code:

function createOption(OptionText, OptionValue){
var temp = document.captcha_form("option");
temp.innerHTML = OptionText;
temp.value = OptionValue;
return temp;
}

function valChange(){
    var firstList = document.getElementById("emailaddress");
    var secondList = document.getElementById("subject");
    while(secondList.hasChildNodes())
        secondList.removeChild(secondList.childNodes[0]);
    switch(firstList.value){
        case "1":{
             secondList.appendChild(createOption("Report Site Browsing Issue", Report Site Browsing Issues));
             secondList.appendChild(createOption("Report Page Errors", Report Page Errors));
             secondList.appendChild(createOption("Other", Other));
             break;
        }
        case "2":{
             secondList.appendChild(createOption("Report Unauthorized Game", Report Unauthorized Game));
             secondList.appendChild(createOption("Report Spam", Report Spam));
             secondList.appendChild(createOption("Report Harassment", Report Harassment));
			 secondList.appendChild(createOption("Report Illegal Activities", Report Illegal Activities));
			 secondList.appendChild(createOption("Request Account Removal", Request Account Removal));
             break;
        }
// ....
        default:{
             secondList.appendChild(createOption("Please select from the first list", ""));
             break;
        }
    }
}
 
window.onload = valChange;

this is the form code

Code:

<div class="mailto_form">
<form method="POST" id="captcha_form" name="captcha_form" action="../includes/mailform.php">
<div style="padding-bottom: 1em;">Choose Recipient: <select name="emailaddress" id="emailaddress" onchange="valChange();">
	<option value=""></option>
	<option value="1">Webmaster</option>
		<option value="2">Admin</option>
		</select>
  </div>
	

<div style="padding-bottom: 1em;">Subject: <br /><select name="subject" id="subject">
  </div>
  
  	<div style="padding-bottom: 1em;">From: <br /><input type="text" name="email" id="email" value="">
	</div>
  
		<div style="padding-bottom: 1em;">Enter the text contained in the image into the text box:
					<br /><img src="../includes/captcha.php" />
					<br /><input type="text" name="userpass" value="">
	</div>
	<div style="padding-bottom: 1em;">Message:
					<br /><textarea name="message" id="message" rows="10" cols="60"><?php echo "</tex" . "tarea>"; ?>				
	</div>
	
	<div style="padding-bottom: 1em;"><input name="submit" type="submit" value="Submit">
	</div>
</form>


</div>

Link to the page http://www.netgamegurus.com/contact/

Hey chaps, hope someone can help with this:
I have a PHP form, with a couple of dynamic Select menus, which are populated from two SQL tables:
// tbl_main_colour:
Code:

ID, NAME
1, Red
2, Blue
3, Green

// tbl_shade_colour:
Code:

ID, NAME, FK_MAIN_COLOUR_ID
1, Light Red, 1
2, Dark Red, 1
3, Light Blue, 2
4, Dark Blue, 2
5, Light Green, 3
6, Dark Green, 3

What I'm after is something to filter the second select option, after the first select option has been chosen
// Select 1:
Code:

Red

// Select 2:
Code:

Light Red
Dark Red

I'm pretty sure this is possible, but not sure how to go about it, any help would be most appreciated.

HI all. How do I determine whether a variable exists in a form. I have a form called "theForm". I want to determine whether the variable "THIRD_PARTY" exists in the form and if it has been set.
Tracy

I have a script that I had written for me that works in IE (I guess its a ActiveX?) but I display it in the HTML page as the below HTML. I want to be able to tell in Javascript if this object is available in IE

Code:

<object id="IEPrinterChecker" classid="CLSID:506974F1-EA53-40C6-940A-4A1D47D5934B" width="0" height="0"></object>

Listed below you can tell I can check if the plugin is available in Firefox without having to specify in the html the object. How can I do this in IE?
Code:

<script language="JavaScript">
var plugin;
if ( window.ActiveXObject ) {
  // IE
  alert("How do I check for the plugin here?");
}	else {
	var type = "application/printer-checker-component;version=1.0.0.1"; // your mimeType
	if (navigator && navigator.mimeTypes){
	   var mt = navigator.mimeTypes;
	   for (var i = 0; i < mt.length; i++){
	      if (mt[i].type == type) {
	         plugin = mt[i].enabledPlugin;
	         if (plugin) break;
	      }
	   }
	}
}
if(plugin)	{
	// insert object and/or test the plugin with script
	alert("plugin is available");
}	else	{
	alert("plugin not available or disabled");
}
</script>

hi..

I want to have a list of words (in an array or whatever just to work)
if the user put that word in a textfield (onblur or onchange) a message popup (alert) appears. (Must be popup alert) but I dont know to code it. HELP!

ex.:
Code:

function badwords() {

var badwords = new Array();
badwords =["badwords1","badwords2","AndSo-On"];

if badwords if written in textfield
  alert("Badwords not allowed");
else
  nothing happen
  just continue with next textfield

}

<input type="text" name="" onBlur=badwords()>

Anyone please help

Hello, I am looking for a way to tell from javascript if a file exists (on the server). I don't mind doing this with a .php script, if I have to, but the javascript still needs to know if the file exists.

I thought the following javascript code might work:

Code:

var file_exists = <?php echo file_exists("OpenTokSessionId.txt"); ?>;

but it didn't. PHP parsed the php code, but it didn't assign the result value to the Javascript variable like its supposed to (or at least, it didn't seem to). When I looked at the page source after I uploaded it to the server, that line of code now looked like this:

Code:

var file_exists = ;

Note that my server is setup to pass files with an .html or .htm extension to the php engine. That is why this kind of stuff can be done. But for some reason, php doesn't seem to be able to output bool values. I tried the following .php script, which I loaded directly in my browser, but it didn't output anything:

PHP Code:
<?php
  function fileExists() {
      return file_exists("OpenTokSessionId.txt"))
  }

  echo fileExists();
?>

So I changed it to the following, and it outputted "File does not exist.", which is the expected result:

PHP Code:
<?php
  function fileExists() {
      if (file_exists("OpenTokSessionId.txt"))
             echo "File exists.";
      else
         echo "File does not exist.";
  }

  fileExists();
?>