Listbox code not working in IE 9 version

i want to transfer one listbox item to other listbox.. below is the code written for it...it works perfectly for chrome,firefox,latest version of IE i.e 10 but not working in IE 9... even its works on development envrmnt but not in production envrmnt. function moveToRightOrLeft(leftCtrl, rightCtrl) {          //leftCtrl=button ctrl with left arrow           //rightCtrl=button ctrl with right arrow             var listLeft = document.getElementById(leftCtrl);             var listRight = document.getElementById(rightCtrl);             if (listLeft.options.length == 0) {               &nbs ...