You need to create the button in much the same way you did the joystick.
It often helps to see it in use so here's a quick demo;
+ Code Snippet// Add a Joystick
addVirtualJoystick ( 1, 88 , 88 , 20 )
// Add a Button
addVirtualButton ( 1 , 12 , 86 , 20 )
setVirtualButtonText ( 1, "Change" + chr ( 10 ) + "Colour" )
// Create a Sprite to show effect
mySprite = createSprite ( 0 )
setSpriteSize ( mySprite , 20 , 20 )
setSpriteOffset ( mySprite , 10 , 10 )
// Set Sprite initial position in two variables
spriteX = 50
spriteY = 30
do
// Change Sprite position variables based on Virtual Joystick inputs
spriteX = spriteX + getVirtualJoystickX ( 1 ) * 5
spriteY = spriteY + getVirtualJoystickY ( 1 ) * 5
// Limit Sprite movement to screen area and above Joystick & Button
if spriteX < 10 then SpriteX = 10
if spriteX > 90 then SpriteX = 90
if spriteY < 10 then SpriteY = 10
if spriteY > 60 then SpriteY = 60
// If button pressed , change sprite colour to a random value
if getVirtualButtonPressed ( 1 ) then setSpriteColor ( mySprite , random ( 128 , 240 ) , random ( 128 , 240 ) , random ( 128 , 240 ) , 255 )
// Set New Sprite Position from Sprite position variables
setSpritePositionByOffset ( mySprite , spriteX , spriteY )
Sync()
loop
This should help you get your head around it.