动态加载Javascript文件

load.js

var script = document.createElement("script");
     
if (script.readyState) {
    script.onreadystatechange = function() {
        if (script.readyState == "loaded" || script.readyState == "complete") {
            script.onreadystatechange = null;
            alert("ie");
        }
    }
} else {
    script.onload = function() {
        alert("nice");
    }
}
     
script.src = "test.js";
document.getElementsByTagName("head")[0].appendChild(script);