code: function(el,arr,fn) {
  	
  		var l=arr.length,i;
  		
  		if ( !lang.isFunction(fn) ) { fn = function(elt,arrElt) { return elt === arrElt; }; }
  		
  		for ( i = 0 ;i < l ; i++ ) {
  			if ( fn.call({}, el, arr[i]) ) { return i; }
  		}
  		
  		return -1;
  	}
docs: Find the position of the given element. (This method is not available in IE 6)
  @static
  @param {Object} el Value to search
  @param {Array} arr The array to search
  @param {Function} (optional) fn A function to define another way to test inclusion of el than === (returns a boolean)
  @return {number} Element position, -1 if not found