// getScript()
// more or less stolen form jquery core and adapted by paul irish

function getScript(url,success){

var head = document.getElementsByTagName("head")[0], done = false;
var script = document.createElement("script");
script.src = url;



// Attach handlers for all browsers
script.onload = script.onreadystatechange = function(){
if ( !done && (!this.readyState ||
this.readyState == "loaded" || this.readyState == "complete") ) {
done = true;
success();
}
};


head.appendChild(script);

}

// usage:
getScript('http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js',function(){
alert('jQuery loaded. yay life')
});