title: AlertDialog Onclick
body: <p>If I have an alertdialog, and I have two buttons, "OK" and "cancel", where the alertdialog only consists of a editText field, how can I create it so that "OK" will only allow the user to continue if the input is not null?</p>
  
  <p>For instance, if input is null and the user presses "OK", it will prompt a toast but wont cancel the alert dialog?  I'm having the issue now where if the input is null and they press "OK", the alertdialog closes.</p>