i got the solution, just you have to use the window orientation event.
following is the code you can use it for the same.
window.onorientationchange = function () { resizeJqGridWidth("GridID", "Grid_wrapper"); }
function resizeJqGridWidth(grid_id, div_id) {
//Resized to new width as per window
$('#' + grid_id).setGridWidth($('#' + div_id).width(), true);
}
Enjoy