function computeForm(form) {

if (form.price.value == null || form.price.value.length == 0) {
   alert("Please enter the selling price of your property.");
   form.price.focus();
} else {

   var Vprice = form.price.value;

   var Vpercent = form.percent.value;
   if (Vpercent >= 1.0) {
      Vpercent = Vpercent / 100.0;
   }

   var Vadvert_cost = form.advert_cost.value;
   var Vcommission = (Vprice * Vpercent);
   form.commission.value = Vcommission;
   

   var Vtotal_cost = form.advert_cost.value;
   var Vthree = (Vprice * ".03");
   form.total_cost.value = Vthree;

   }
}