function CalculateOrder(paypal) {

 if (paypal.coup.value == "CORP10")
 {
 paypal.discount_rate_cart.value = "10";
 
 }
  if (paypal.coup.value == "FBMEMBER10")
 {
 paypal.discount_rate_cart.value = "10";
 
 }
  if (paypal.coup.value == "SUNCORP20")
 {
 paypal.discount_rate_cart.value = "20";
 
 } 
  if (paypal.coup.value == "LBIRD10")
 {
 paypal.discount_rate_cart.value = "10";
 
 }  
 
  if (paypal.coup.value == "HB10")
 {
 paypal.discount_rate_cart.value = "10";
 
 }   
 
 
 
 
 
 
}