executing function after loading a extern script.

loadAndExecute.js

var load, execute, loadAndExecute;
load = function(a, b, c) {
  var d;
	d = document.createElement("script"), d.setAttribute("src", a), b != null && d.addEventListener("load", b), c != null && d.addEventListener("error", c), document.body.appendChild(d);
	return d
}, execute = function(a) {
	var b, c;
	typeof a == "function" ? b = "(" + a + ")();" : b = a, c = document.createElement("script"), c.textContent = b, document.body.appendChild(c);
	return c
}, loadAndExecute = function(a, b) {
	return load(a, function() {
		return execute(b)
	})
};