最近有个项目用到了动态添加行这个功能，在网上找到了源码实现了功能，就是不知道下面这段代码具体什么意思

function findObj(theObj, theDoc){
var p, i, foundObj;
if(!theDoc) theDoc = document;
if( (p = theObj.indexOf("?")) > 0 && parent.frames.length)
{
theDoc = parent.frames[theObj.substring(p+1)].document;
theObj = theObj.substring(0,p);
}
if(!(foundObj = theDoc[theObj]) && theDoc.all)
{
foundObj = theDoc.all[theObj];
}
for (i=0; !foundObj && i < theDoc.forms.length; i++)
{
foundObj = theDoc.forms[i][theObj];
}
for(i=0; !foundObj && theDoc.layers && i < theDoc.layers.length; i++)
{
foundObj = findObj(theObj,theDoc.layers[i].document);
}
if(!foundObj && document.getElementById)
{
foundObj = document.getElementById(theObj);
}
return foundObj;
}