function obj(id,doc){
	if(id==""){
		return null
	}
	if(doc==undefined||doc==""){
		return document.getElementById(id)	
	}
     else {
		return doc.getElementById(id)
	}
}


//获得对象（按三种情况IE，NS）
function GetObj(objName){
	if(document.getElementById){
		return eval('document.getElementById("'+objName+'")')	}
    else if(document.layers){
		return eval("document.layers['"+objName+"']")	}
    else {
		return eval('document.all.'+objName)
	}
}

var getFFVersion=navigator.userAgent.substring(navigator.userAgent.indexOf("Firefox")).split("/")[1]
//extra height in px to add to iframe in FireFox 1.0+ browsers
var FFextraHeight=getFFVersion>=0.1? 16 : 0 

function dyniframesize(iframename) {
var pTar = null;
if (document.getElementById){
pTar = document.getElementById(iframename);
}
else{
eval('pTar = ' + iframename + ';');
}
if (pTar && !window.opera){
//begin resizing iframe
pTar.style.display="block"

if (pTar.contentDocument && pTar.contentDocument.body.offsetHeight){
//ns6 syntax
pTar.height = pTar.contentDocument.body.offsetHeight+FFextraHeight; 
}
else if (pTar.Document && pTar.Document.body.scrollHeight){
//ie5+ syntax
pTar.height = pTar.Document.body.scrollHeight;
}
}
}