how to validate form

i know who to validate the form . i am using css for the display that's why <ul><li>.

the normal way of form.fnam=="" id not throwing any error(i am using alert())

does use of <ul> <li> has anything to do

 

What programming language do you want to use? You can do it with Javascript, PHP, etc etc etc... be a little more specific for some examples

 

sorry if i am a bit rude but this is a javascript forum page right. i have sorted out all the php issues but want the user to be warned before he submits

 

plz give me the exact code to validate at least one of the field

 

Your onsubmit should look like this:

onsubmit="return validate(this)">

HTML:

The Javascript part:

<script type="text/javascript">
function validate() {

var error=''; // an empty error string
  if ( document.getElementById('F1').value == '' ) { // id="F1" is empty
  error = error+"\n- F1 cannot be empty.";
  }
  if ( document.getElementById('F1').value.length > 15 ) { // id="F1" has more than 15 characters
  error = error+"\n- F1 cannot be more than 15 characters.";
  }

// add more validation here

if (error != '') { // error string is not empty
alert('Please correct the following error to continue:'+error)
return false;
} else {
return true;
}

}
</script>

HTML:

 

this is not throwing any alerts
here is the actual code
http://forums.digitalpoint.com/showthread.php?t=1237858