it's not so much that the form is redirecting, you are just setting these events to happen on the form post.
unlike javascript, PHP validation must happen on the server, so the form must completely post before it can occur. The return false in javascript is used to prevent the form from posting entirely, this cannot be emulated in php since the form must be posted for the php processor to be able to inspect the form data.
you would need to set the initial value of the form elements to use the posted data:
For example:
Name : <input type="text" name="t1" id="t1" value="<?php echo(isset($_POST["t1"])?$_POST["t1"]:""); ?>" />
