Axe puzzle!

.Please opim.
.my subroutine!
.      Thanks!
.      -Albert

.Bonus points:
.Guess what
.this code
.does!

.6 inputs,
.all integers
Lbl ABC
If r5=r6
For(X,r1,r2)
For(Y,r3+(r6*r4),r3+(r4-1)+(r6*r4))
Pxl-Change(X,Y)
End
End
DispGraph
Else
If r6>r5
For(N,1,r4)
For(X,r1,r2)
Pxl-Change(X,r3+(r5*r4)+(N-1))
Pxl-Change(X,r3+(r6*r4)+(N-1))
End
DispGraph
End
Else
For(N,1,r4)
For(X,r1,r2)
Pxl-Change(X,r3+(r5*r4)+(r4-N))
Pxl-Change(X,r3+(r6*r4)+(r4-N))
End
DispGraph
End
End
End
Return