Error message running iupgl.wlua

[Frank Meier-Dörnberg <frank@...>]

Dear IUP, LuaGL or Lua for Windows maintainers

1st, let me say: Many thanks for all the great stuff you made.

2nd, unfortunately the Iupcanvas.wlua example does not work right "out 
of the box" as packaged with Lua For Windows.
The error message 
"...a\5.1\examples\iup\ctrl\iupglcanvas\iupglcanvas.wlua:12: attempt to 
call global 'glClearColor' (a nil value)" occours.

It is easy to fix:
Line 7 have to be:  gl = require( "luagl" )

Frank

P.S.
same applies to iupgl.wlua