I'm new here in the forum so i guess i should say Hello first

. Also i'm new to asm.
Okay. Here's the problem ax does not seem to increment here
macro drawVLine xCoord,yCoord, dist, pColor {
local pangloop
push ax
push cx
mov ax,yCoord
mov cx,dist
pangloop:
plotPixel xCoord,ax,pColor
inc ax
dec cx
cmp cx,0
jne pangloop
pop cx
pop ax
}
but after i've change ax to bx it incremented. I could say that it incremented because i could see a horizontal in mode 13h. But for ax i only see a pixel.
Is this a bug or there just something wrong with my code?