This cool little script makes a form submit in a pop up window, so the original page doesn't change. Thought it's very useful.
Note: I do not take credit for it. Found the script here:

http://javascriptkit.com/script/script2/form2popup.shtml

Here it is:

<script type="text/javascript">

//I don't take credit for this script! Found it here:
//http://www.javascriptkit.com/script/sc
//     ript2/form2popup.shtml

    function createTarget(t){
    window.open("", t, "width=600,height=550");
    return true;
}

</script>
<form name="sampleform" method="POST" action="/cgi-bin/formsubmit.pl"
onsubmit="return createTarget(this.target)" target="formtarget"></form>

Hope this is useful to some.