Simple JAVA help

[noswad]

I have this code:

<script Language="JavaScript">
<!--
function Form1_Validator(theForm)
{
	if (theForm.username.value == "")
  {
    alert("Please enter a username");
    theForm.username.focus();
    return (false);
  }
}
//--></script>

Can anyone develop this so that if u user enters non a-z, 0-9 characters, an error message popsup?

I have tried and tried with no luck

Thanks for reading.

 

[Noobie]

http://www.hscripts.com/scripts/JavaScript/alphanumeric-check.php

 

[noswad]

Hi

Thanks for the reply but I dont understand Javascript at all lol.

 

[jetbrains]

The question is about javascript,not java question