yes we certainly can not disable browse buttons cause its not ours its browser specific but we can disable certain function keys like F5 to refresh browser and F1 for Help menu in IE explorer, here is the code spinet that will disable browser F5 button to refresh browser contents.
document.onkeydown = function() {
if(event.keyCode == 116) {
event.returnValue = false;
event.keyCode = 0;
return false;
}
}
place this code anywhere in JavaScript and your keyboard short cut key for F5 will be disabled for that particular page. 116 is a numeric code for F5. You can disable any button by finding numeric code for it