Calc Total Claim

//Calculation
function totalClaim(){
  var total = parseFloat(getValueById('fieldname')) * parseFloat(getValueById('fieldname2')) * getValueById('fieldname3');
  getField("fieldname4").value = roundNumber(total, 2).toFixed(2);
}
//event handler
getField("fieldname").onkeyup= function(){
  totalClaim();
}
  getField("fieldname").onkeyup= function(){
  totalClaim();
}