// generic file loader
//
function loadScript(url, callback){
	var script = document.createElement("script")
	script.type = "text/javascript";

	if (script.readyState){  //IE
		script.onreadystatechange = function(){
			if (script.readyState == "loaded" || script.readyState == "complete"){
				script.onreadystatechange = null;
				callback();
			}
		};
	} else {  //Others
		script.onload = function(){
			callback();
		};
	}

	script.src = url;
	document.getElementsByTagName("head")[0].appendChild(script);
}