Javascript validation for usable form

Hi,

Anyone has sample or tutorial for javascript validation for usable form? I encounter error on this script.

For reference, promotitle is radio button to set on/off for promotitletext (input textfield), ticketdeadline is radio button to set on/off for ticketdeadlinetext (input textfield). When i set promotitle to off, my ticketdeadlinetext is not validate. Please advice, thanks in advance.

<script>
function validation()
{

obj = document.create_offerform;

if (obj.promotitle[0].value == "yes"){
if (obj.promotitletext.value == "")
{
alert("Please enter your promotion title.");
obj.promotitletext.focus();
return false;
}
}

if(obj.ticketdeadline[0].value == "yes"){
if (obj.ticketdeadlinetext.value == "01/01/1900")
{
alert("Please enter your ticketing deadline.");
obj.ticketdeadlinetext.focus();
return false;
}
}


}
</script>

 

Try this code. If it doesn't work, then provide the link to a demo page

<script>
function validation(){
	obj = document.create_offerform;
	if (obj.promotitle[0].checked){
		if (obj.promotitletext.value == ""){
			alert("Please enter your promotion title.");
			obj.promotitletext.focus();
			return false;
		}
	}

	if(obj.ticketdeadline[0].checked){
		if (obj.ticketdeadlinetext.value == "01/01/1900"){
			alert("Please enter your ticketing deadline.");
			obj.ticketdeadlinetext.focus();
			return false;
		}
	}
}
</script>

Code (markup):

 

Yes, it works! Thanks so much Aragorn !