Messages

Hi,
I have this code:

Code (glbasic) Select Expand

LET a=5
PRINT a, 100, 100
SHOWSCREEN
MOUSEWAIT
END

And these warnings and errors:

Code (glbasic) Select Expand

*** Configuration: WIN32 ***
precompiling:
GPC - GLBasic Precompiler V.7.861 SN:8bee8179 - 2D, WIN32
"Hello World.gbas"(3) warning : probably unassigned variable : a
"Hello World.gbas"(3) error : variable is not explicitly defined : a

My question - why? Everything seems to be fine... LET command causes that, but why? What is wrong here?