function tabSwitch(new_tab, new_content) {  
     document.getElementById('products_menu').style.display = 'none';  
     document.getElementById('brands_menu').style.display = 'none';  
     document.getElementById(new_content).style.display = 'block';     
   
     document.getElementById('products_tab').className = '';  
     document.getElementById('brands_tab').className = '';  
     document.getElementById(new_tab).className = 'current';        
}