Jquery Script not working in Internet Explorer

Question

I have this script working fine in Chrome but in IE 8 or 9, this code is not working:

$(document).on("mousedown", '#CentroCusto_new option', function (event) {
    debugger;
    alert('oi');
    event.returnValue = false;
    this.selected = !this.selected;
    event.preventDefault();
});

• In IE: F12 is open.
• Debugger and Alert is not called.
• jQuery v1.10.2
• No errors in console.
• I tried to change document to 'body', but not working too.
• When I remove option, function is called

How to solve this? I think IE is not accepting this selector, but why?

JSFIDDLE

Answer 1

debugger; is pausing execution of your code - which is why alert() isn't firing