JavaScript - Check If Check Box Is Checked On Name Array

Hiya,
I'm looking for some guidance on a part of some coding practice I'm stuck on!

I've created a shopping cart using javascript, the items save to the arrays etc and it all works fine. If the user adds the same product again to the cart the quantity is added onto the previous quantity that is already in the cart.
To check if the item is already in the cart I've ued the below code, but what it does is update the quantity for the first cart, and when it updates the quantity for the second item it updates the quantity but keeps adding the same product to the cart in seperate elements of the array as well (if that makes sense?

here are the two functions used:

Code:

function additem(id) {
itemName = document.getElementById('name' + id).innerHTML;		itemQuantity = parseInt(document.getElementById('quantity' + id).value);
itemPrice = parseFloat(document.getElementById('price' + id).innerHTML);
if(numitems == 0){	
items[++numitems] = new Item(itemName,itemPrice,itemQuantity);
displaycart();
}
else{
checkarray(id, itemName, itemQuantity, itemPrice);
}
		
}

function checkarray(id, itemName, itemQuantity, itemPrice){

for(i=1;i<=numitems;i++) {
if(items[i].name == itemName){
items[i].quantity += parseInt(document.getElementById('quantity' + id).value);
displaycart();
return true;
}
		
items[++numitems] = new Item(itemName,itemPrice,itemQuantity);
}	
 
}

It may jsut be a simple mistake I've made but it's been bugging me a lot and I can't seem to fix it, any help/pointers would be greatly appreciated.

Hello

I am trying to find a way to use the check all javascript code to select all my checkboxes within a while...loop.

Codes goes as follows:

within the header on the top of page 1:
<SCRIPT LANGUAGE="JavaScript">
function CheckAll(chk)
{
for (i = 0; i < chk.length; i++)
chk[i].checked = true ;
}

function UnCheckAll(chk)
{
for (i = 0; i < chk.length; i++)
chk[i].checked = false ;
}
</script>

The code that displays the checkboxes, which is a page included onto page 1:
echo "<a class='comp' onclick='singleHideandShow({$row['pr_id']})' style='cursorointer'>{$row['propname']}</a><p>";
$propqry = mysql_query("SELECT * FROM users WHERE propid={$row['pr_id']}");
//using the hide and show id number, once clicked it will display the below contents
echo "<div id={$row['pr_id']} style='display:none;'>";
while($propf = mysql_fetch_assoc($propqry)) {
if($propf['uactive'] == "yes") {
$pactive = "active";
} else {
$pactive = "deactivated";
}
//displays the information from the DB with a checkbox
echo "<form name='myform' id='formmsg' method='post' action='profile.php?paction=edit&find=none' >";
echo "&nbsp;&nbsp;&nbsp;&nbsp;<input type='checkbox' name='check_list' value='{$propf['us_id']}'>&nbsp;&nbsp;<a href='profile.php?paction=edit&pid={$propf['us_id']}' /><img src='../images/secure/edit.png' name='Edit' border='0' /></a>&nbsp;<a href='profile.php?paction=delete&pid={$propf['us_id']}' /><img src='../images/secure/delete.png' name='Delete' border='0' /></a><label class='cuser'>&nbsp;&nbsp;{$propf['fname']} {$propf['lname']}, &nbsp;&nbsp; ({$propf['uname']}), &nbsp;&nbsp; {$pactive}</label><br>";

}
echo "</form>";
echo '<p><input type="button" name="Check_All" value="Check All" onClick="CheckAll(document.myform.check_list)"> <input type="button" name="Un_CheckAll" value="Uncheck All" onClick="UnCheckAll(document.myform.check_list)"> <p>';
echo "</div>";


I receive the following error message when I click on the Check All button.

Message: 'length' is null or not an object
Line: 15
Char: 13
Code: 0
URI: http://www.domainname.com/profile.ph...edit&find=none



Can anyone help me figure this out?

this code is supposed to
ask the users name
and say how many letters in it
get 2 random numbers
ask user to add them
if right say Well Done!
if wrong say
Sorry, you are wrong.

when i run this nothing comes up
whats wrong?

thanx



Code:

<script>
var firstName = "";
var numLetters = 0;
firstName = prompt("Hi, what's your first name?", "");
numLetters = firstName.length;
alert ("Did you know there are " + numLetters + " letters in your name?");
var num1 = Math.floor(Math.random()*9) + 1;
var num2 = Math.floor(Math.random()*9) + 1;
var answer;
var useranswer;
answer = num1+num2;
useranswer = promt("What is" + num1 + "+" + num2 + "?");
If (answer = useranswer)
{
     alert("Well done!");
}
else
{
     alert("Sorry, you are wrong.");
}
</script>

I have a text input box that resets to blank when the user enters an alpha character, it also checks for the number 0 as it has to be greater than 0 too... when I submit the form it is blank the variable changes to blank (as I use parseInt to convert it to an integer at a later stage)

What can I do to check and see if it is NaN value?
(I've tried isNaN() and it did not do what I wanted it to)

I have NO knowledge of Javascript at all but borrowed and attempted to adapt one I found. It is a Firefox bookmarklet designed to highlight in different colours both certain words or the ending "ing" on a word in a text document that has been saved as html. Basically it is a device for helping novel writers rid their manuscripts of redundant words and overuse of the 'ing" words. In works in part but doesn't pick up all "ing" endings. For someone who know what their doing I imagine it would take more than a few minutes to read and correct. Many thanks to anyone who can help. Here is the Javscript:

javascript:var%20verbsRE=/(\b)(about|actually|almost|already|appear|approximately|basically|close to|even|eventually|exactly|finally|here|just|kind of|nearly|now|practically|really|seem|simply|somehow|somewhat|sort of|suddenly|then|there|truly|utterly|while|as|appear|felt|gaped|gawked|gazed|glanced|hear|heard|knew |looked|noticed|observed|peered|peeped|regarded|saw|scanned|see|seeing|seemed|smelled|stared|studied |surveyed|tasted|viewed|watched)(\b)/gi;var%20ingRE=/(\w)(ing)(\b)/gim;function%20HL(node){if(node.hasChildNodes){var%20hi_cn;for(hi_cn=0;hi_cn<node.childNodes.length; hi_cn++){HL(node.childNodes[hi_cn]);}}if(node.nodeType==3){var%20tempNodeVal=node.nodeValue;if(verbsRE.test(tempNodeVal)){tempNodeVal= tempNodeVal.replace(verbsRE,"$1<span%20style='background-color:yellow;color:black;border:1px%20solid%20black;'>$2</span>$3");tempNodeVal=tempNodeVal.replace(ingRE,"$1<span%20style='background-color:#0ff;color:black;border:1px%20solid%20black;'>$2</span>$3");newNode=document.createElement('span');newNode.innerHTML=tempNodeVal;pn=node.parentNode;pn .replaceChild(newNode,node);}}}HL(window.document.getElementsByTagName('body')[0]);

This is perhaps a somewhat trivial point but it's bugged me a couple of times recently and I wondered if anyone out there had any thoughts on the matter.

Essentially I have an action that can happen many times but I want to record whether it has happened at least once. I know we are talking about a trivial amount of processing and code here but is there any real difference between the following two methods:

Code:

myCheck: false,

myRepeatedlyCalledFunction: function() {
     this.myCheck = true;

     // do some stuff
}

vs

Code:

myCheck: false,

myRepeatedlyCalledFunction: function() {
     if(this.myCheck === false) {
          this.myCheck = true;
     }

     // do some stuff
}

thoughts?

Hello, I have never used javascript before, so this might be a very basic question. I have a script on my blog which places a stumbleupon button on the page.

This is the code that calls the script:

Code:

<script src="http://www.stumbleupon.com/hostedbadge.php?s=5"></script>

Today I went to my blog and it was taking a long time to load, it turns out because stumbleupons site is down so the script can't be accessed. A whole lot of other stuff on the page just doesn't load until it times out though, so it takes like 3 minutes for the page to load.

What I want to know is can I test if the script is reachable and only call it if it is, so that if there is a 403 or 404 error it just won't even try to load it and continue loading the rest of the page??

Any help is greatly apprectiated!

Thanks.

Is it possible to find out if an element is using a scroll bar for overflow?

like I need to be able to change the size of something if there is any overflow....

Hi, I am not familiar with javascript, I am using a check box validation tool that I copied from this site:

http://mediazeal.com/checkbox-validator.htm

This is my webpage:

http://rbhlc.weebly.com/discover-hea...n-jyutsu.html#

Right now when you click the buy now button (when the checkbox is checked) i does not go to the hyperlink. How can I get the button to go to my link when the checkbox is validated?

Here is my code: (the authorize.net account it a Test Account.. so it won't link to anything sensitive)

<form name="form" method="post" action="#" onSubmit="return checkme();">
<table cellpadding="0" cellspacing="0" border="0">

<tr>
<td colspan="2" align="center"><input type="checkbox" name="agree" value="agree_terms"> I agree to the terms</td>
</tr>

<tr>
<td colspan="2" align="center">

<form name="PrePage" method = "post" action = "https://scotest.authorize.net/payment/CatalogPayment.aspx">
<input type = "hidden" name = "LinkId" value ="3569f626-b8a8-4974-8ceb-35ca08a63087" />
<input type = "image" src ="//testcontent.authorize.net/images/buy-now-gold.gif" /> </form>

</td>
</tr>

Thank you for your support.

I am trying to add values from 6 text boxes and display its sum automatically in 7th text box. This is not working. Please help.





function calculate_a() {
var a = document.getElementById('Para_A_A1_score').value ;
var b = document.getElementById('Para_A_A2_score').value ;
var c = document.getElementById('Para_A_A3_score').value ;
var d = document.getElementById('Para_A_A4_score').value ;
var e = document.getElementById('Para_A_A5_score').value ;
var f = document.getElementById('Para_A_A6_score').value ;
var g = (a+b+c+d+e+f) ;
document.audit_billing_IE.product_name4.value = g ;
}



Quote:
Below is the html form code that should automatically display the total value without clicking on any submit or send button

<tr>
<td> Parameter A </td>
<td colspan='3'> <input type="text" name="product_name4" id="product_name4" onchange="calculate_a(this);" /> </td>
</tr>

I am trying to get a link that when clicked it will check all the checkboxes in my form.

My problem is that my values are stored in an array:
<INPUT TYPE=\"checkbox\" name=\"emailArray[]\" value=\"$email\">


print"<br><a href=\"#\" onClick=\"checkAll()\">check all</a><br>";

Here is my javascript function :
function checkAll(){
alert('hi');
var df = document.selectEmailForm.elements;

for (var i = 0; i < df.length; i++) {
if (df[i].name == "emailArray[]" ) {
document.selectEmailForm.emailArray[i].checked=true;
}
}
}

Any ideas? Any help is greatly appreciated.
Thanks for your time!

This is the code part that fails it's if check.

Code:

while (n<=30)
	{
	var slot='#slot'+n;
	$( slot ).data({no: n, id: itemId[i], name: itemName[i], equip: itemEquip[i], lvl: itemLvl[i], bonus: itemBonus[i], rstr: itemRStr[i], rdef: itemRDef[i]});
	$( slot ).draggable({ handle: slot, stack: slot, revert: "invalid", snap: "div#"+itemEquip[i], snapMode: 'inner',
	start: function(event, ui) 
	{
	$('div#'+$(this).data('equip')).css({'border': '2px dashed #0066CC', 'background': 'rgba(255,255,255,0.2)'})
	.droppable
	({
		drop: function(event, ui)
		{
			if (pLvl>=$('.ui-draggable-dragging').data('lvl') && pStr>=$('.ui-draggable-dragging').data('rstr'))
			{	
			alert(pLvl+", "+$('.ui-draggable-dragging').data('lvl'));
			$('.ui-draggable-dragging').css({'display':'none'});
			$('div#'+$('.ui-draggable-dragging').data('equip')).html
			(
			 "<img src='items/equipped/"+$('.ui-draggable-dragging').data('name')+$('.ui-draggable-dragging').data('id')+".png' />"
			)
				  $.ajax({type:"GET", url:"items/change.php", data:"id="+$('.ui-draggable-dragging').data('id')+"&no="+$('.ui-draggable-dragging').data('no'), cache:false, timeout:5000,
													error: function() {
														$('div.nogood').html
														(
														"There was an error. Please inform us about it in the forum."
														).css({'width':'400px','margin-left':'-200px'});
                                                       $( 'div.nogood' ).fadeIn(500, away);
													   function away()
													   {
														$( 'div.nogood' ).delay(2000).fadeOut(500);
													   };
                                                }
                                        });

			
			}
			else 
			{
				alert("HUh");
				$( 'div.nogood' ).fadeIn(500, away).css({'width':'400px','margin-left':'-200px'});;
				$('.ui-draggable-dragging').draggable({revert: true});
				if (pLvl<$('.ui-draggable-dragging').data('lvl'))
				{
				alert("Good");
				}
				else if (pStr<$('.ui-draggable-dragging').data('rstr'))
				{
				$('div.nogood').html("Not enough strength.")
				}
				function away()
				{
					$( 'div.nogood' ).delay(1400).fadeOut(500);
				};
			
			}
		}
	});
	},
	stop: function(event, ui) 
	{
		$('div#'+$(this).data('equip')).css({'border':'none', 'background':'transparent'}).droppable("destroy");
	}
	});
		n++;
		i++;
	}

This if comparison if (pLvl>=$('.ui-draggable-dragging').data('lvl') && pStr>=$('.ui-draggable-dragging').data('rstr')) somehow goes through. After the if statement I check the values with the alert but it displays 5 for pLvl and 10 for the draggables data (which are the correct numbers) so can anyone tell me why does this if statement still go through when pLvl is lower?

I need to create some javascript code that asks a user a series of yes/no questions. Depending on how the user answers it will direct them to additional yes/no questions or simply stop with a message that they are not eligible.

I need something similar to this site: http://www.kingfoundation.com/Grants...lity-Quiz.aspx

Any help to develop this code would be much appreciated as I am a fairly inexperienced developer.

I was wondering if there was a simple way of notifying a user who has entered an incorrect postcode? I have found numerous answers to this problem but i am sure there is a simpler way to do it as ones i have found have rows and rows of code.

Help is much appreciated