title: how to perform Condition check, before segue unwind
body: <p><code>VC1</code> segues to <code>VC3</code> which has a keypad and predetermined lowest number acceptable entered into a label. User can either add a number to the end of this string or delete a number. When "Accept" key is pressed, the string.toInt() is passed to <code>VC1</code> and segue is unwind via </p>
  
  <pre><code>@IBAction func unwindToSegue(segue: UIStoryboardSegue, sender:UIStoryboardSegue){
      BetLabels[betSourceR].text = BetReturned
      if BetReturned == ""{} else{
          Chip[betSourceR].hidden = false}}
  </code></pre>
  
  <p>I need to achieve so that no string.toInt() lower than minimum is accepted and some sort of override func that stops the unwind from happening while posting a warning to the user that this input is not acceptable.</p>
  
  <p>How would i achieve this when?
   <strong>Maybe place something in <code>VC3</code> func prepareForsegue? Or another method?</strong></p>
  
  <p>Or could i disconnect the "accept" from the unwind, and make a IBAction that if under minimum{ warn user, return to VC3} else {VC1.unwindToSegue}</p>