code not working

code not working

why does my this code is not running? please help me 
$('#pmForm').submit(function(){$('input[type=submit]', this).attr('disabled', 'disabled');});
function sendPM ( ) {
      var pmSubject = $("#pmSubject");
 var pmTextArea = $("#pmTextArea");
 var sendername = $("#pm_sender_name");
 var senderid = $("#pm_sender_id");
 var recName = $("#pm_rec_name");
 var recID = $("#pm_rec_id");
 var pm_wipit = $("#pmWipit");
 var url = "php_parsers/private_msg_parse.php";
      if (pmSubject.val() == "") {
           $("#interactionResults").html('<img src="images/round_error.png" alt="Error" width="31" height="30" /> &nbsp; Please type a subject.').show().fadeOut(6000);
      } else if (pmTextArea.val() == "") {
  $("#interactionResults").html('<img src="images/round_error.png" alt="Error" width="31" height="30" /> &nbsp; Please type in your message.').show().fadeOut(6000);
      } else {
  $("#pmFormProcessGif").show();
  $.post(url,{ subject: pmSubject.val(), message: pmTextArea.val(), senderName: sendername.val(), senderID: senderid.val(), rcpntName: recName.val(), rcpntID: recID.val(), thisWipit: pm_wipit.val() } ,           
  function(data) {
  $('#private_message').slideUp("fast");
  $("#interactionResults").html(data).show().fadeOut(10000);
  document.pmForm.pmTextArea.value='';
  document.pmForm.pmSubject.value='';
  $("#pmFormProcessGif").hide();
           });
 }
}