var ImageSwitch = {
	"over" : function(event) {
		var el = PythonEvent.element(event);
		if (el.src.length > 0)
		{
			var root = el.src.substring(0, el.src.length - 7);
			el.src = root + '_ov.gif';
		}		
	},
	"out" : function(event) {
		var el = PythonEvent.element(event);
		if (el.src.length > 0)
		{
			var root = el.src.substring(0, el.src.length - 7);
			el.src = root + '_up.gif';
		}
	}
}

var ImageSwitchRules = {
	"img.switchImage" : function(element) {
		PythonEvent.observe(element, "mouseover", ImageSwitch.over);
		PythonEvent.observe(element, "mouseout", ImageSwitch.out);
	}
}

Behaviour.register(ImageSwitchRules)