hello...help me rapidly..
query is that.. when we select the mail from the select tag and then automatically display the two text box like user name and contact no.. how i do this...? but remeber it that without use button....i hope as soon as i vl get my perfect ans...

This can be done in many ways, here is the one quick solution..

function PerformAction() {
    var SelectedValue = document.Form.SelectValue.value;
    if(SelectedValue == "mail") document.getElementById("VisibleID").style.visibility="visible";
    else document.getElementById("VisibleID").style.visibility="hidden";
    return false;
<form action="" method="get" name="Form">
  <select onchange="PerformAction()" name="SelectValue">
    <option value=""></option>
    <option value="mail">Mail</option>
  <div style="visibility:hidden;" id="VisibleID"> Username :
    <input name="" type="text" />
    Contact Number :
    <input name="" type="text" />