need help with grid based game

Strict 

Import mojo


Global screenWidth:Int = 640
Global screenHeight:Int = 480 
 
 
Class Board
  Field x:Int 
  Field y:Int 
  Field cols:Int = 8
  Field rows:Int = 8 
  Field offset:Int = 1
  Field lvl:Int[][]
  Field size:Int = 40
  Field gridOffset:Int 
  
	  		Method New()
	  			
	  			gridOffset = (screenWidth -((size + 2) * rows)) / 2
	  			x = gridOffset
	  			y = 100
	  		End  
	  		
	  		Method level:Int()
	  		
	  		
	  			Return 0 
	  		End 
	
			Method Draw:Int()
				
				For Local j:Int = 0 until cols
					For Local i:Int = 0 Until rows
					'white border
				SetColor( 255 ,255, 255)
				DrawRect( x+i*(size+2), y+j*(size+2), size+4, size+4)
				
					'inner boxes
				SetColor( 255, 100, 100)
				DrawRect( x+2+i*(size+2), y+2+j*(size+2), size, size)
					End 
				End 
			
				Return 0 
			End 

End 

Class Pieces Extends Board
 
  
  Field candy:Image
  Field jellyBean:Int  
  Field gumDrop:Int  
  Field lolliPop:Int  
  Field mint:Int  
  Field mix:Int  

	  		Method New(frame:int)
	  			candy = LoadImage("size1/candy.png",40,40,16,Image.MidHandle)
	  			
	  				 Seed = Millisecs()
		  			 jellyBean  = Rnd(0,3)
					 gumDrop  = Rnd(4,7)
					 lolliPop  = Rnd(8,11)
					 mint  = Rnd(12,15)
					 mix  = Rnd(1,4)
	  		End  
	  		
	  		Method pickCandy:Int()	  
		  			  jellyBean  = Rnd(0,4)
					  gumDrop  = Rnd(4,8)
					  lolliPop  = Rnd(8,12)
					  mint  = Rnd(12,16)
					  mix  = Rnd(1,5)
				    
	  			Select mix 
	  				Case 1
	  				mix = jellyBean
	  				Case 2
	  				mix = gumDrop
	  				Case 3 
	  				mix = lolliPop
	  				Case 4 
	  				mix = mint
	  			End 
	  		
	  			Return 0 
	  		End 
	
			Method Draw:Int()
				 
				'need to make candyList
				'For loacal spread:= Eachin candyList
				For Local j:Int = 0 until cols 
					For Local i:Int = 0 Until rows 
						DrawImage(candy,x+(size+4)/2+i*(size+2),y+(size+4)/2+j*(size+2),0,1,1,mix)
					End
				End 
				'End 
				Return 0 
			End 

End 

Class crushcandy Extends App

  Field board:Board
  Field pieces:Pieces
  Field candyList:List<Pieces> = New List<Pieces>

		Method OnCreate:Int() 
		 
			  SetUpdateRate(3)
			 
			  board = New Board
			  pieces = New Pieces
			  candyList.AddLast(New Pieces(pieces.mix))
			 
			Return 0 		
		End 
		
		
		Method OnUpdate:Int()
		 
			pieces.pickCandy()
			
		
			Return 0 
		End 
		   
		
		Method OnRender:int()
			Cls(40,35,34)
			 
			 board.Draw()
			 SetColor(255,255,255)
			
			 For Local piece:= Eachin candyList
			 	piece.Draw()
			 End 
			Return 0 
		End 
End 



Function Main:Int ()

	New  crushcandy()
	
	Return 0
End