importScript.js

var importScript = (function (oBody) {
	return function (sSrc, fOnload) {
		var oScript = document.createElement('script');
		oScript.type = 'text\/javascript';

		if (typeof fOnload === 'function') {
			oScript.onerror = function (evt) {
				fOnload(new URIError('The script ' + evt.target.src + ' is not accessible.'));
			};
			oScript.onload = function () {
				fOnload();
			};
		}

		oBody.appendChild(oScript);
		oScript.src = sSrc;
	}
})(document.body || document.getElementsByTagName('body')[0]);