function validate()
{  
  //validate price
  var o = document.getElementById("CALC_PurchasePriceDollars");
  var v =o.value.replace("$","").replace(",",""); 
  if (v.length == 0 || isNaN(v)) {  
     alert("Please enter a dollar amount for the purchase price of the property.");
     o.focus();
     return false   
  }
  //validate interest rate
  o=document.getElementById("CALC_InterestRatePercent");
  v =o.value; 
  if (v.length == 0 || isNaN(v)) {  
     alert("Please enter a percentage value for the mortgage interest rate.");
     o.focus();
     return false   
  }
  return true;
}