function showHide(num,amount) {

   // hide div below all radio choices
   divs=window.document.getElementById('eventChoice').getElementsByTagName('DIV');
   for (var i=0; i<divs.length; i++) {
       divs[i].style.display="none";
   }

   // show div below the radio choice=num
   divs[num].style.display="block";

   window.document.registration.choice[num].checked=true;

   //change form variable=choiceNum
   window.document.registration.choiceNum.value=num;
	   
   // write total amount on page and change form variable=amount
   if (!amount || amount==0) {
      if (num==0) { writeTotal(125); }
      else if (num==1) { writeTotal(500); }
      else if (num==2) { writeTotal(500); }
      else if (num==3) { writeTotal(1000); }
   } else {
      writeTotal(amount);
   }

}

function writeTotal(amount) {

   // write total amount on page
   window.document.getElementById('total').innerHTML=amount;
   // change form variable=amount
   window.document.registration.total.value=amount;
}
 
function changeTotal(object) {
  value=object.options[object.selectedIndex].value;
  temp = value.split(' ');
  writeTotal(temp[0]);
}