function openWindow(){
var a=confirm("是否打开新窗口"); if(a==true)
{
var b=prompt("请输入要打开的网址","http://www.imooc.com/");
if(b!=null)
{
window.open(b,'_blank','width=400,height=500,menubar=no,toolbar=no');
}
<script type="text/javascript">
function add(){
var p1 = document.getElementById("p1");
p1.className="one";
}
function modify(){
var p2 = document.getElementById("p2");
p2.className="two";
}
