How do I code a simple dice gambling game?

enter image description hereHere is my current code:

• Html

  Dice - Roll above 50 to win

• Javascript

  var randomNum = Math.floor((Math.random() * 100) + 1); var pass = 50;

  if ( randomNum > pass ) { msg = 'You won! '; } else { msg = ' You lost! ' }

  var el = document.getElementById('info'); el.textContent = msg + 'You rolled: ' + randomNum;

Scenario:

1. Person clicks button for free credits
2. Button adds 5 Credits to his balance
3. He clicks a button to run the dice
4. If he wins +10 to his balance, if he loses -5 to his balance

How would someone code that? ( I am a beginner in js ) Thanks!