Call documentGetElementById without event

[KeredDrahcir]

I need to change the background of an input box depending on if a radio button on a form has been selected or not.
I'm trying to do it using a documentGetElementById which is called when the php checks the radio buttons. There is no event to call the documentGetElementById. Can I still call it without an event?

[Dormilich]

a) the call is document.getElementById() (JavaScript is case sensitive)
b) if you do processing with PHP, it’s too late for JavaScript.

[KeredDrahcir]

Is there some way I can change the style of something using php similar to the way Javascript uses;
documentGetElementById('id').style.backgroundColor ='#df8ff9';

[Dormilich]

no. PHP and Javascript have a totally different way of "interacting" with HTML.

[KeredDrahcir]

All I want to do as the page load is to check a POST value and if it is unset or one value set the background colour of an input box, and if it is another value set the background colour of a different box.
Surely there must be a simple way of doing this.

[Dormilich]

if you want to check a POST value, you need a server-side language like PHP or ASP. then everything else is just a modification of the source code.

[KeredDrahcir]

Define the boxs you want to change will their ID name. After the boxes use something like this:

<?
  if ((!strcmp($_POST['preferred'],"email")) || (!($_POST['preferred'])))
  {
    echo "<script type="text/javascript">
      document.getElementById('email').style.backgroundColor='#d7ebff'; document.getElementById('phone').style.backgroundColor='#ffffff';
    </script>";
  }
  else
  {
    echo "<script type="text/javascript">
      document.getElementById('phone').style.backgroundColor='#d7ebff'; document.getElementById('email').style.backgroundColor='#ffffff';
    </script>";
  }
?>
 

[Dormilich]

I wouldn’t use JavaScript, if I could edit the CSS right away.

<?php
$color1 = '#d7ebff';
$color2 = '#fff';
if ((!strcmp($_POST['preferred'],"email")) || (!($_POST['preferred'])))
{
$color1 = '#fff';
$color2 = '#d7ebff';
}
?>
 
#email {
    background-color: <?= $color1; ?>;
}
 
#phone {
    background-color: <?= $color2; ?>;
}