function sendMail() 
{
  var data="singupEmail="+$("singupEmail").value;
  var aj = new Ajax.Request("siteForUpdate.php", {
  method:'post',
  parameters: data,
  onComplete: getResponse
  });
}

function getResponse(oReq) {
$("singupEmail").value="";
$('blank_alert_uname').innerHTML = oReq.responseText;

}