vertical horizontal scroll not working

I have a really big table with columns exceeding 40. Now I want to scroll horizontally but the scroll is not working. Browser scrollbar comes though.

$(document).ready(function() {
$('#example').dataTable({
"oTableTools" : {
"sScrollY": 200,
"sScrollX": "200%",
"sScrollXInner": "110%",
}
});