(function(){
	
/**
 * jQuery plugin to animate some element moving to the location of another element
 * @author Derek Fowler
 * $('.ep_Add').eq(0).flyTo('#excursionHelp');
 * 
 * $('.ep_Add').flyTo('#excursionHelp').queue(function () {
 *     $(this).remove();
 *     $(this).dequeue();
 * });
 *
 */

jQuery.fn.flyTo = function(selector, settings) {
	settings = jQuery.extend({
		clone: true,
		opacity: 0.5,
		duration: 2000,
		finishHidden: true
	}, settings);
	

	var toReturn = null;
	
	var destinationOfMove = jQuery(selector).get(0);
	
	if(destinationOfMove) {
		var destTop = getSumOfValsUpTree(destinationOfMove, document.body, 'offsetParent', 'offsetTop');
		var destLeft = getSumOfValsUpTree(destinationOfMove, document.body, 'offsetParent', 'offsetLeft');
						
		toReturn = this.map(function(){
			
			var startTop = getSumOfValsUpTree(this, document.body, 'offsetParent', 'offsetTop');
			var startLeft = getSumOfValsUpTree(this, document.body, 'offsetParent', 'offsetLeft');
			
			var thingToMove;
			if(settings.clone) {
				thingToMove = jQuery(this).clone();
			}
			else {
				thingToMove = jQuery(this).remove();
			}
			
			thingToMove.css('position', 'absolute');
			thingToMove.css('top', startTop + 'px');
			thingToMove.css('left', startLeft + 'px');
			thingToMove.css('opacity', settings.opacity);
									
			thingToMove.appendTo(document.body);
						
			thingToMove.animate({ top: destTop + 'px', left: destLeft + 'px' }, settings.duration );
			
			if(settings.finishHidden) {
				thingToMove.queue(function () {
	 				$(this).remove();
	 				$(this).dequeue();
				});
			}
			
			return thingToMove.get(0);
			
		});
		
	}
	
	// return an empty jQuery object if we've nothing to return
	if(toReturn === null){
		toReturn = jQuery();
	}
	return toReturn;
	
};

function getSumOfValsUpTree(elmFrom, elmAncestor, strParentProp, strPropToSum) {
	var s = 0;
	/*
	 * IE's root level offset parent is HTML, not BODY
	 * so if we're looking for offset relative to the
	 * page then just let it run to null.
	 */
	if(strParentProp == 'offsetParent' && elmAncestor == document.body) {
		elmAncestor = null;
	}
	while(elmFrom[strParentProp] !== elmAncestor && elmFrom[strParentProp] !== null) {
		s += elmFrom[strPropToSum];
		elmFrom = elmFrom[strParentProp];
	}
	return s;
}

})();