Grab the vendor prefix of the current browser.

vendor_prefix.js

// Based on: http://lea.verou.me/2009/02/find-the-vendor-prefix-of-the-current-browser/
var VENDOR_PREFIX = (function () {
	
	var regex = /^(Webkit|Khtml|Moz|ms|O)(?=[A-Z])/,

		styleDeclaration = document.getElementsByTagName("script")[0].style;

	for (var prop in styleDeclaration) {
		if (regex.test(prop)) {
			return prop.match(regex)[0].toLowerCase();
		}
	}
	
	// Nothing found so far? Webkit does not enumerate over the CSS properties of the style object.
	// However (prop in style) returns the correct value, so we'll have to test for
	// the precence of a specific property
	if ("WebkitOpacity" in styleDeclaration) { return "webkit"; }
	if ("KhtmlOpacity" in styleDeclaration) { return "khtml"; }

	return "";
}());