jQuery get the selected dropdown value on change

val is a method, not a property.

use it like val()

If you are using it many places, i would assign it to a local variable and use it thereafter.

Also you can use the $.now() function to get the unique time stamp. It is equal to DategetTime();

$('.dropone').change(function() {    
    var item=$(this);
    alert(item.val())
    $(".droptwo").empty();
    $(".droptwo").load("ajaxdropdown.aspx?drpType=room
                        &roomid=" +item.attr("value") + "&ts=" + $.now());
});

You must obtain the value using a method, not a property. Use this:

alert($(this).val())

$('.dropone').change(function() {
  var val = $(this).val(); 

  // OR

  var val = this.value;
})