How to make virtual joystick (Windows Store)?

Hello, I need some help - I dont know how to make joystick. My idea is to make button (GUITexture) and programm it for change value of "Vertical axis" to 1 when press. I hope you understand it. I want just that button to imitate w/upper arrow. And I want four buttons for moving and one to jump, my problem is that I dont know how to programm this (my lang is C#). ---------- More 'graphic' presentation of my idea: - BUTTON1 -> tap -> Vertical axis = 1; - BUTTON1 -> !tap -> Vertical axis = 0; - BUTTON2-> tap -> Vertical axis = -1; - BUTTON2-> !tap -> Vertical axis = 0;