I am wondering how those drag and drop widgets cancel text selection in the dragging element and other elements in the page. I tried the following code which works in IE8 (cannot select text) but does not work (can still select text) in Firefox.
<!DOCTYPE html>
<html>
<body>
<p>Hello World</p>
<script type="text/javascript">
document.onmousemove = function() {
return false;
}
</script>
</body>
</html>