function Suppliers()
{
document.getElementById('supplier').className="on";
document.getElementById('buyer').className="off";
document.getElementById('tb1').className="opent";
document.getElementById('tb2').className="closet";
}


function Buyers()
{
document.getElementById('supplier').className="off";
document.getElementById('buyer').className="on";
document.getElementById('tb1').className="opent1";
document.getElementById('tb2').className="closet1";
}