map editor 2

Take a look at these two function.

Function place()
	
	If MouseDown(KEY_MOUSELEFT)
	
		For Local i:Int = 0 To mapx-1
			For Local j:Int = 0 To mapy-1
				map[i,j] = curtile
			Next
		Next
	EndIf
		
End Function

Function update()

	For Local x:Int = 0 To mapx-1
		For Local y:Int = 0 To mapy-1
			DrawImage tiles,x*50,y*50,map[mapx-1,mapy-1]
		Next
	Next
	
End Function

What am I doing wrong?

here is all the code

Strict

Rem 
MapEditor Version 0.1
Author   : Amon
Compiler : BlitzMax
EndRem

Incbin "backblock.png"
Incbin "icon.png"

Graphics 800,600,16,0

SetMaskColor 0,0,0

Global tiles:TImage = LoadAnimImage("incbin::backblock.png",50,50,0,9,MASKEDIMAGE)
Global icon:TImage = LoadImage("incbin::icon.png",MASKEDIMAGE)

Global tileframe:Int = 0

Global mapx:Int = 16
Global mapy:Int = 12

Global curtile:Int = 0

Global map:Int[mapx,mapy]



Repeat 

	Cls
	
		nexttile()
		place()
		update()		
		drawcurser()
				
	Flip
	
Until KeyHit(KEY_ESCAPE)

Function drawcurser()
	
	Local xpos:Int = MouseX()/50*50
	Local ypos:Int = MouseY()/50*50
	
	DrawImage tiles,xpos,ypos,curtile
	
End Function

Function nexttile()

	If MouseHit(KEY_MOUSERIGHT)
	
		curtile:+1
		
		If curtile > 8 Then curtile = 0
		
	EndIf
	
End Function

Function place()
	
	If MouseDown(KEY_MOUSELEFT)
	
		For Local i:Int = 0 To mapx-1
			For Local j:Int = 0 To mapy-1
				map[i,j] = curtile
			Next
		Next
	EndIf
		
End Function

Function update()

	For Local x:Int = 0 To mapx-1
		For Local y:Int = 0 To mapy-1
			DrawImage tiles,x*50,y*50,map[mapx-1,mapy-1]
		Next
	Next
	
End Function