         
         print(fith)
         
+        // display result to user
         resultLabel.text = "\(fith)"
         
     }

        i = i/12
        print(i)
        
        let first = (1+i)**n
        let second = first * i
        let third = p * second

    // calculate payment on tap of calculate button
    @IBAction func calculateButtonAction(sender: AnyObject) {
        
        // Set vars to grab string data from input, then convert to double.
        n = loanTerm
        p = (loanAmountTextField.text as! NSString).doubleValue
        i = (rateTextField.text as! NSString).doubleValue
