js获取页面内iframe的高度

function SetCwinHeight(f){
var iframe=$G(f);
try{
var bHeight = iframe.contentWindow.document.body.scrollHeight;
var dHeight = iframe.contentWindow.document.documentElement.scrollHeight;
var height = Math.max(bHeight, dHeight);
iframe.height = height;
}catch (ex){}
$G(f).contentWindow.nameIncreasing();
}