JS 动态创建select

var text = "test";
var params_select = document.getElementById("params_select");
//创建标签
var opt = document.createElement("option");
//创建文本
var _text = document.createTextNode(text);
//把文本赋给标签
opt.appendChild(_text);		
//属性赋值	
opt.setAttribute("value",objs[m].keyid);
opt.setAttribute("selected","selected"); 
//添加
params_select.appendChild(opt);