function CalculateOrder(form)
{

if (form.os0.value == "Platinum")
 {
 form.amount.value = 1000.00;
 form.item_number.value = "001-4-6";
 }
 
if (form.os0.value == "Gold")
 {
 form.amount.value = 750.00;
 form.item_number.value = "001-8-12";
 }

if (form.os0.value == "Silver")
 {
 form.amount.value = 500.00;
 form.item_number.value = "001-12-18";
 }
 
 if (form.os0.value == "Bronze")
 {
 form.amount.value = 250.00;
 form.item_number.value = "001-12-18";
 }
 
}