PHP - How Can I Set A Default Variable If One Has Not Been Set In The Url?

Hello, i know this is a very silly question but it bothers me to know the reasoning behind it. My application has a design where the functions are stored in functions.php and variables are stored in variables.php. There are some functions that have variables that i might change often and the reason i don't directly use them in the argument itself is so that in future if i have to change the default argument's value , then i wouldn't have to scroll through all the functions and look for it. I have a slippery memory i know i will be able to remember it better if i store custom global variables separately and custom global functions separately.

I tried searching these forums for this but its giving me a message like "search daemon not found" or something like that..

Anyways , coming to the point, i know that PHP doesn't accept variables as default arguments but may i know the reasoning behind this? If i understand the reasoning behind this i know it will stick better in my head.So..why does a function not allow a variable as a default value?

Or if anyone has a link to explaining this behaviour in PHP, i would appreciate it if you could pass it on!

Thank you

I have a simple form that edits student information.  I have several fields that I have a drop down list pulled as an array from a separate table.  I would like the information that is already entered on the student to be the default but still have the drop down list available if the item was entered in error. For example:  Drop down list of all the states of America, OH was entered for the student, when the edit form comes up for State in Address I would like OH to be the default but still have the list to choose if OH was entered in error. I have tried selected = $selected but then the entire drop down changed to OH.  I am very, very much a beginner in this

<?php
   // list of possible modules comes from database
         
          $state_array=get_states();
       
       
          //display as a drop down list for end user to choose
        if (!is_array($state_array))
      {
         echo "<p>No States are currently available<p>";
         return;
      }
    
             
       
          foreach ($state_array as $row)
        {
               echo "<option value=\"".($row['stateid'])."\"";
               // if existing state, put in current catgory
               echo "<strong>  ".($row['stateid'])."</strong><br />";       
               echo "<option select=\"selected\">OH";
          }
         
   ?>

I have a few dropdown forums and would like it to select the current values that are requested.

Code: [Select]
global $filename,$fileid,$filetype,$filedir,$fileby;
  global $months,$pg;


echo "<h2>Search Files</h2>";
echo "<p>";
  echo "<form name = 'File_Search' action = '#' method = 'POST'>";
echo "<table border=\"0\" width=\"100%\"><tr>";
echo "<td>File Name<br><input type = 'text' name = 'name'></td><td>File Type<br><select name = 'type'>
<option value = '0'>All Types</option>
  <option value = 'o'>Official Files</option>
<option value = '1'>Quests</option>
  <option value = '2'>Graphic/Spritesheets</option>
  <option value = '3'>Entity/Scripts</option>
  <option value = '4'>Sound/Music</option>
  <option value = '5'>QuestPack/Programs</option>
  <option value = '6'>Miscellaneous</option>
  </select></td>";
  echo "<td>Order By<br><select name = 'order'>
  <option value = '0'>Last Updated</option>
  <option value = '1'>ID</option>
  <option value = '2'>Name</option>
  <option value = '3'>Downloads</option>
  <option value = '4'>Rating</option>
<option value = '5'>Points</option>
  <option value = '6'>Random</option>
  </select></td>";
  echo "<td>Acending?<br><select name = 'dir'><option value = '0'>False</option><option selected value = '1'>True</option></select></td>";
echo "</tr><tr><td rowspan = '4'><input type = 'submit' name = 'search' value = 'search'></td></tr></table></form>";
echo "</p>";

So if the $filetype equals 2 I want the dropdown box to show "Graphic/Spritesheets" by default. BTW Official Files is not actually a type so that's why I chose to give it a small letter o and will work the same way as All Types but run a different function.

$fileby is used for the OrderBy field.
$filedir is for the Acending field.
The other data is for the other parts of the script.

If you like you can give advice on the name's default because you may have a better method then what I have in my head.

How do I set the date format so that it's always going by the UTC date?

I've used:
Code: [Select]
date_default_timezone_set('UTC');
but, when I change my date on my computer, the date changes on the website.

This is really confusing me, googled different ways for like 10/20 minutes and can't find anything.

If anyone can help it'd be great,

Thanks,
Andy.

I am loading a link with ajax. When the link pops on the screen and I click it, I get redirected to my 404 page and my lightbox doesn't load.

If the link pops in and I refresh my browser, then I click the link my lightbox will show up.

How can I do a prevent default on the <a href> in pure JS? No frameworks please.