function Products()
{
document.getElementById('product').className="on";
document.getElementById('service').className="off";
document.getElementById('tb3').className="productt";
document.getElementById('tb4').className="servicest";
}


function Services()
{
document.getElementById('product').className="off";
document.getElementById('service').className="on";
document.getElementById('tb3').className="productt1";
document.getElementById('tb4').className="servicest1";
}