accessing global variable in a function and putting this variable's value in ajax

accessing global variable in a function and putting this variable's value in ajax

  2. var preCounter = 0;
  3. var counter = 0;
  4. $("#addQ").click(function(){
  5. $.ajax({
  6. url : "qtemp.php",
  7. type : "post",
  8. data : "axn=qtype&cntr="+counter+"&pcntr="+preCounter
  9. }).done( function(msg) {
  10. });
  11. });

  13. });
'preCounter' is not passing value in ajax while varible 'counter' passing value. please help me, thanks in advance