function tab(id) {

	if (id == '1' ) 
		{
			document.getElementById('1').style.display = 'block';
			document.getElementById('item_1').className="active";	
			
			document.getElementById('2').style.display = 'none';
			document.getElementById('item_2').className="inactive";			
			document.getElementById('3').style.display = 'none';
			document.getElementById('item_3').className="inactive";	
		}

	if (id == '2' ) 
		{
			document.getElementById('2').style.display = 'block';
			document.getElementById('item_2').className="active";	
			
			document.getElementById('1').style.display = 'none';		
			document.getElementById('item_1').className="inactive";		
			document.getElementById('3').style.display = 'none';
			document.getElementById('item_3').className="inactive";		
		}
		
	if (id == '3' ) 
		{
			document.getElementById('3').style.display = 'block';
			document.getElementById('item_3').className="active";	
			
		
			document.getElementById('1').style.display = 'none';
			document.getElementById('item_1').className="inactive";		
			document.getElementById('2').style.display = 'none';
			document.getElementById('item_2').className="inactive";		
			
		}
}