...you don't want that ugly iframe hanging around, visible to your users, so you can close it by removing the node.
Here's a dirty example:
//create a js variable that contains the url and js variables to be passed.
var iframe1=document.createElement("iframe"); iframe1.src=myUrl; body.appendChild(iframe1);
//next, remove the element node from the document so the users won't see the iframe.
A return from the php script to the client browser can be made ie,
, if back-end validation is done.
?><script>alert("A user name is required");</script><?
This works well in IE5.x and NN7.x.