Web Development

If your statement "Netscape 4 (Windows)" implies NN4 and not 'for', then DIV is not supported. NN4 is not a standards compliant browser and thus Netscape has abandoned it to be more DOM (Document Object Model) compliant. NN4 uses layers.

Testing with NN6+ or IE4+ should render your code correctly as long as your javascript function is called validate(), which IS case-sensitive.

I would also remove the action="otherpage.htm" and put it in your validate() routine:
Ex.

function validate() {
var iname='';
iname = document.form1.textfield;
if(!iname.value) {
alert('Field cannot be blank');
iname.focus();
return false;
} else {
document.form1.action="otherpage.htm";
return true;
}
}

This way your form will never be submitted unless it passes your validation tests.