function TestAjax()
{
  var UserName = $("#txtUserName").val();
  $.ajax({
    url:"AjaxCheckUserName.htm",
    async:false,
    success:function(data){
      alert(data);
    }
  });
  alert('Test');
  $.ajax({
    url:"AjaxHandler.ashx",
    async:false,
    data:"UserName=" + UserName,
    success:function(data){
      $("#divAjax").html(data);
    },
    error:function(msg){
      alert(msg.responseText);
    }
  });
}