function roll_over(elements){
	switch(elements){
		case 'home':
			document.getElementById('links').style.backgroundPosition = '0px -27px';
		break;
		
		case 'mail':
			document.getElementById('links').style.backgroundPosition = '0px -54px';
		break;
		
		case 'sitemap':
			document.getElementById('links').style.backgroundPosition = '0px -81px';
		break;
	
		case 'off':
			document.getElementById('links').style.backgroundPosition = '0px 0px';
		break;
	}
}