var coup1="VDSN10DX";


function CalculateOrder(form) {

 if (form.coupon.value == coup1)
 {
 form.discount_rate.value = "10";
 form.discount_rate2.value = "10";
 form.on5.value = "Coupon";
 form.os5.value = "VDSN10DX - Discount 10%";
 }
}