function changeParentBGR(up_down){
 	var obj = document.getElementById('wassersport');
	
	if(up_down == 'down'){
		obj.style.backgroundPosition = '0 -212px'
	}
	if(up_down == 'up'){
		obj.style.backgroundPosition = '0 0'
	}
	if(up_down != 'up' && up_down !== 'down'){
		alert('Wrong parameter');
		return false;
	}
	return;
 }