Validating a textfield once a checkbox is ticked

[MAC]

Hi
Can anyone help?

I have a simple contact form which I have so far managed to validate, the one function I do not know how to do is this-

If the browser selects the checkbox I need them to fill out a textfield as well(10 digit number to be exact) or the form doesn’t validate, if they de-select or do not select the checkbox I want the form to validate without it.

Hope that makes sense

Thanks MAC

[Jordan]

If you want to do this before the submit button is pressed then you will need to use JavaScript. Here is some sample code:

<script Language="JavaScript">
<!-- 
function Blank_TextField_Validator()
{
// Check the value of the element named text_name
// from the form named text_form
if (text_form.text_name.value == "")
{
// If null display and alert box
alert("Please fill in the text field.");
// Place the cursor on the field for revision
text_form.text_name.focus();
// return false to stop further processing
return (false);
}
// If text_name is not null continue processing
return (true);
}
-->
</script>

<form name="text_form" method="get" action="http://www.codeave.com/html/get.asp" 
 onsubmit="return Blank_TextField_Validator()">