Random Falling Items Help

I am making a game on codea, and I want to add random falling items from the top of the screen, Please, any help is appreciated!

Someone posted this some time ago (sorry pal, i didnt write your name in, just claim youself as the author)


--Main

supportedOrientations(PORTRAIT_ANY)

function setup()

    displayMode(FULLSCREEN)  
    objectTable = {}
    lastGenerated = ElapsedTime
    interval = 1
    num = 1  
    table.insert(objectTable,Objects(math.random(1,WIDTH-1),math.random(1,4),num))
   
end

function draw()
  
    spriteMode(CENTER)
    sprite("Cargo Bot:Opening Background",WIDTH/2,HEIGHT/2,WIDTH,HEIGHT)
    pushStyle()

    spriteMode(CENTER)
    randomObjectGenerate()   
    popStyle()       
end

function randomObjectGenerate()
    for k,v in pairs(objectTable) do 
        v:draw()    
    end
    if ElapsedTime - lastGenerated > interval then
        lastGenerated = ElapsedTime
        num = num + 1
        table.insert(objectTable,Objects(math.random(1,WIDTH-1),math.random(1,4),num))   
    end
    for k,v in pairs(objectTable) do 
        if v.a.y < 0 or (v.a.x > WIDTH or v.a.x< 0) or v.a.info.id == 0 then
            table.remove(objectTable,k)
            v.a:destroy()
            v.a = nil
            v=nil           
        end             
    end
end


--Objects

Objects = class()

function Objects:init(x,cat,id)
    -- you can accept and set parameters here
    
    self.a = physics.body(CIRCLE,20)
    self.a.x = x
    self.a.y = HEIGHT
    self.a.gravityScale = 1
    self.a.restitution = 0.0
    self.a.interpolate = true
    self.asleepingAllowed = true
    self.flag = true
    self.category = cat
    self.a.info = {}
    self.a.info.id = id
    
end

function Objects:draw()
    pushMatrix()
    translate(self.a.x, self.a.y)
    if self.category == 1 then
        sprite("Cargo Bot:Condition Blue",0,0,50,50)
    elseif self.category == 2 then
        sprite("Cargo Bot:Condition Green",0,0,50,50)
    elseif self.category == 3 then
        sprite("Cargo Bot:Condition Red",0,0,50,50)
    elseif self.category == 4 then
        sprite("Cargo Bot:Condition Yellow",0,0,50,50)         
    end
    popMatrix()
end
    
function Objects:touched(touch)
    -- Codea does not automatically call this method
end

And there is this excellent program from space monkey:
http://www.twolivesleft.com/Codea/Talk/discussion/2014/bouncing-balls/p1

Thanks, but is it possible to add sprites to this and gravity to move the sprite to pick up the items? Anyone who helps will be credited.