how to increase height of popup in jquery mobile iframe

how to increase height of popup in jquery mobile iframe

Hello All,
I want to increase the size of Popup Iframe.
The default size is height="320" width="480"
I want to increase it
height="1024" width="768"
(Basically need to increase height)

I have changed the size in java script (Some part is as under)
  1. $( "#popupMap" ).on({
             popupbeforeposition: function () {
                 var size = scale( 480, 320, 0, 1 ),
                     w = size.width,
                     h = size.height;

Here I have changed
  1. $( "#popupMap" ).on({
             popupbeforeposition: function () {
                 var size = scale( 1024, 768, 0, 1 ),
                     w = size.width,
                     h = size.height;
But it does not helped me.
can anybody help me to increase the height of Popup
Thanks !