Js Code used to determine whether an element is a child element of another element

Of course there are many methods, but I think it is one of the simplest ways to determine whether an element is a child element of another element.
Method:
Copy codeThe Code is as follows:
Function isParent (obj, parentObj ){
While (obj! = Undefined & obj! = Null & obj. tagName. toUpperCase ()! = 'Body '){
If (obj = parentObj ){
Return true;
}
Obj = obj. parentNode;
}
Return false;
}

View demo: http://demo.jb51.net/js/2012/isParent/
Thanks to hafeyang's message, js judges whether an element is another element of the sub-element related methods and contains method, you can look at situ zhengmei Article http://www.jb51.net/article/26158.htm