function switchProductTab( tab_number ) 
{
	switch(tab_number) {
		case 2:
			document.getElementById('product_tabinhalt_1').style.display = 'none'; 
			document.getElementById('product_tabinhalt_2').style.display = 'block';
			document.getElementById('product_tab_1').className = 'tab_left';
			document.getElementById('product_tab_2').className = 'tab_left_active';
			break;
		case 1:
			document.getElementById('product_tabinhalt_1').style.display = 'block'; 
			document.getElementById('product_tabinhalt_2').style.display = 'none';
			document.getElementById('product_tab_1').className = 'tab_left_active';
			document.getElementById('product_tab_2').className = 'tab_left';
			break;
			default:
			break;
	}
}