Vanishing draw_string

OK, i should have been a more diligent student before asking, but i don't have a lot of time these days 

Why the string at the end of my script suddenly disappears and doesn't last on display for 1500 ms ?

--[[
@title test
]]

require("drawings")

-- few script lines ---------------------------------

draw_string( 30, 120, ("text"), 258, 259, 2, 2)
sleep(1500)
draw.clear()
exit_alt()

What usually happens when drawing any string (or other object) is that the Canon UI overwrites it.   So the trick is to constantly rewrite in a loop.

That's why the Lua drawing  module is so useful.  If you use it to create the information you want on the screen then you can just call draw.​redraw() from a loop.

In your case, try this :
--[[
@title test
]]

require("drawings")

-- few script lines ---------------------------------

for i=0,i<15,1 do
   draw_string( 30, 120, ("text"), 258, 259, 2, 2)
   sleep(100)
end

draw.clear()
exit_alt()

getting this error msg (at for i ... line):
"attempt to compare nil with number" 

getting this error msg (at for i ... line):
"attempt to compare nil with number" 

darn
--[[
@title test
]]

require("drawings")

-- few script lines ---------------------------------

for i=0,15,1 do
   draw_string( 30, 120, ("text"), 258, 259, 2, 2)
   sleep(100)
end

draw.clear()
exit_alt()

noticed the typo before your reply 

The drawning is fine now.
Thank you again, glad to have a mentor like you.

noticed the typo before your reply 

Wasn't a typo.  C syntax vs Lua throws me sometimes when I'm constantly switching back and forth.  That's why I usually test before I post - but that one seemed so simple that, well, you know ...