Displaying Objects, Adding Sound, Using Tables and Event Listener in Corona SDK

gistfile1.lua

--James Fajardo is the name of the font that I am using
local advice = display.newText("Take a Walk", 0, 0, "James Fajardo", 70)
--while placing the "advice" display object, regard its center point as a reference
advice: setReferencePoint ( display.CenterReferencePoint )

_W=display.contentWidth --screen's width
_H=display.contentHeight --screen's height

--place the center x and y of the "advice" object to specified points below. 
advice.x=_W/2
advice.y=_H/2

--adviceBox table holds some advices as element
adviceBox={"Take a Walk", "Choose to Be Happy", "Listen", "Care About Beloved Ones", "Smile", "Listen Good Music", "Don't Give Up", "Imagine" }
--colorBox table holds rgb tables as element. Rgb tables hold r,g and b values in order. 
colorBox=
{
  {255, 215, 0}, --gold
  { 50, 205, 50}, --limegreen
  {210, 105, 30}, --chocolatte
}

--button sound is loaded first to be played later.
local buttonSound = audio.loadSound("button.wav")

local adviceButton = display.newRoundedRect(0,0,300,100, 20)
adviceButton: setReferencePoint(display.BottomCenterReferencePoint)

adviceButton.x = _W/2
adviceButton.y = _H-50

local adviceText = display.newText("Tell Me More", 0, 0, nil, 35)
adviceText: setReferencePoint(display.CenterReferencePoint)
adviceText.x = _W/2
adviceText.y=adviceButton.y-adviceButton.height/2
--adviceText's color is set to black(rgb code is 0,0,0)
adviceText: setTextColor ( 0, 0, 0 )
--adviceText is brought to front of the adviceButton
adviceText: toFront()

--chooseRandom randomly changes the advice text and background color of the screen and play the button sound.
local chooseRandom=function(event)
	--Changing text randomly
	local i = math.random(1, #adviceBox) -- i is the lucky advice 
	advice.text=adviceBox[i]
	
--Changing background color randomly
	local a = math.random(1, #colorBox) -- a is the lucky rgb color code
	display.setDefault("background", colorBox[a][1], colorBox[a][2], colorBox[a][3])
	--Playing a sound
	local buttonChannel = audio.play(buttonSound)
end

--chooseRandom function is called when the adviceButton is tapped.
adviceButton: addEventListener("tap", chooseRandom)