getElementById获取value时,提示null
代码如下:
在alert(input_obj.value); 输出为null
<html>
<head>
<title></title>
</head>
<body onLoad="abc();">
<iframe id="res" src="http://localhost/zbhb/zhifa/zhongdian/input1.jsp" frameborder=0 scrolling="yes" height="100%" width="100%"></iframe>
</body>
</html>
<script>
function abc(){
var ifr;
var ifr_ready;
var ifr_document;
var input_obj;
var input2_obj;
var form_obj;
ifr = document.getElementById("res");
if( ifr ){
try{
ifr_ready = ifr.document.readyState;
}
catch(e){
//errror: zi ji chu li
return;
}
if ( ifr_ready )
{
if ( (ifr_ready == 'complete')){
ifr_document = ifr.document;
if( ifr_document ){
input_obj = ifr_document.getElementById("QName");
alert(input_obj.value);
input_obj.value = "sss"; //zhi ding zi ji de yong hu ming
}
return;
}
}
else
{
setTimeout( abc, (window.opera ? 250 : 100));
}
}
}
</script>