速度快，同步（需要引入jquery）

var oBody = document.getElementById("frame3_id").contentWindow.$("body");

var str = "<div>...</div>"
var scriptTag = document.getElementById("frame3_id").contentWindow.document.getElementById("pop");
if(!scriptTag){
oBody.append(str);
}

var oScript= document.createElement("script");
oScript.id = "oScript1";
oScript.type = "text/javascript";
oScript.src="/test.js";
var oTag1 = document.getElementById("frame3_id").contentWindow.document.getElementById("oScript1");
if(!oTag1){
oBody.append(oScript);
}

document.getElementById("frame3_id").contentWindow.test(); // 調(diào)用frame3_id 中的test()方法

var str = "<div>...</div>"
var popDiv=document.createElement('div');
popDiv.style.xx = xxx;
popDiv.id = "pop";
popDiv.innerHTML = str;
var oBody = document.getElementById("frame3_id").contentWindow.document.getElementsByTagName("body")[0];
var oHead = document.getElementById("frame3_id").contentWindow.document.getElementsByTagName("head");

if(oHead && oHead.length){
oHead = oHead[0];
}else{
oHead = oBody;
}

var elemDivTag = document.getElementById("frame3_id").contentWindow.document.getElementById("pop");
if(!elemDivTag){
oBody.appendChild(popDiv)
}

var oScript= document.createElement("script"); （css類似）
oScript.id = "oScript1";
oScript.type = "text/javascript";
oScript.src="/test.js";
var scriptTag = document.getElementById("main").contentWindow.document.getElementById("oScript1");
if(!scriptTag){
oHead.appendChild(oScript);
}
oScript.onload = oScript.onreadystatechange = function(){
if ((!this.readyState) || this.readyState == "complete" || this.readyState == "loaded" ){
document.getElementById("main").contentWindow.test(); // test()方法 在 引入的js文件中
}else{
console.info("can not load the oScript2.js file");
}
}