an improvement if bar cmd fails
Code:
gosub glcd_init
GLCD_CLR


do
for n=0 to 120 step 1
GLCDDHL 0,0,n,1
next n


for n=120 to 0 step -1
GLCD_CLR 0,0,120,1 ;is a lot more efficient
GLCDDHL 0,0,n,1
next n
loop