Retrieves the number of immediate child nodes of the current element or a zero if the element does not contain any child nodes. childElementCount does not return all child nodes, only child nodes that are nodeType =1, or element nodes.http://msdn.microsoft.com/en-us/library/ie/ff974793%28v=vs.85%29.aspx
and then comes a paragraph with id="testPar" which has a strong tag nested in it.
And in this nested paragraph I remind you that there are empty text nodes between the elements.
if (document.getElementById('testRoot').childElementCount) alert('childElementCount is supported, result is ' + document.getElementById('testRoot').childElementCount); else alert('childElementCount is not supported');