The javascript in the HEAD of this document.
<SCRIPT>
function check(){
(document.f1.t1.value==document.f1.t2.value)?alert("fields identical"):alert("fields
different");
}
function checkAlt(){
if (document.f1.t1.value==document.f1.t2.value){
alert("fields identical")}
else{
alert("fields different")
}
}
</SCRIPT>