function showhide(id,id1){
	document.getElementById('a1').className="";
	document.getElementById('a2').className="";
	document.getElementById('a3').className="";
	document.getElementById('a4').className="";
	document.getElementById('a5').className="";
	document.getElementById(id1).className="current";
	document.getElementById('pozycjonowanie').style.display ='none';
	document.getElementById('linki-sponsorowane').style.display ='none';
	document.getElementById('serwisy-www').style.display ='none';
	document.getElementById('wizerunek').style.display ='none';
	document.getElementById('reklama').style.display ='none';	
	document.getElementById(id).style.display ='block';
}