function add_events_to_class(elements_class,element_event,element_function){
	
	var stuff = $$(elements_class);
	for (var i = stuff.length - 1; i >= 0; i--){
		Event.observe(stuff[i],element_event,element_function);
	};
	
}

function emptyInput(event){
	var element = event.element();
	if(element.value == 'szukaj'){ element.value = ''; }
	element.removeClassName('empty');
	
}


Event.observe(window, 'load', function() {
 	var empty = $$('input.empty');
	Event.observe(empty[0], 'focus', emptyInput);
});