Finding DOM node index

Question

I want find the index of a given DOM node. It\'s like the inverse of doing

document.getElementById(\'id_of_element\').childNodes[K]

I want

Answer 1

RoBorg's answer works... or you could try...

var k = 0;
while(elem.previousSibling){
    k++;
    elem = elem.previousSibling;
}
alert('I am at index: ' + k);