code: function (node) {
  		  	var parent = node.parentNode,
  		  		i = -1,
  		  		child;
  	  		while (parent && (child = parent.childNodes[++i])){
  				 if (child === node){
  					 return i;
  				 }
  			}
  	  		return -1;
  		}
docs: get the child index of a node. Used to create a node path
  
  @param  {DOM Node} node
  @return {Int}