var coup1="MAP50OFF";
var coup2="map50off";
var coup3="1FREEMAP";

function CalculateOrder(form) {

 if (form.text1.value == coup1)
 {
 form.discount_rate.value = "50";
 form.discount_rate2.value = "50";
 form.on0.value = "Coupon";
 form.os0.value = "MAP50OFF - Discount 50%";
 }
  if (form.text1.value == coup2)
 {
 form.discount_rate.value = "50";
 form.discount_rate2.value = "50";
 form.on0.value = "Coupon";
 form.os0.value = "map50off - Discount 50%";
 }
  if (form.text1.value == coup3)
 {
 form.discount_rate.value = "100";
 form.discount_rate2.value = "100";
 form.on0.value = "Coupon";
 form.os0.value = "1FREEMAP - FREE";
 }
}