Check for Null ?

I have managed to use supernote as part of a MS .hta
After tweaking the regex a bit, the only real tweak I had to do was a check for null here:

if (srcElm  != null){
if (srcElm.nodeType != 1)  srcElm = srcElm.parentNode;
}


I am not the JS master, and my understanding of how Supernote works is mediocre , I cant seem to tell if will have any noticable adverse effects. I seems as if it shouldnt matter since the srcElm would essentially be changing as the mouse moves anyways? Either way supernote is great!!