Problems with command export !

In a shell I export vars (export VAR1=) with a script but not set the vars but I directly use export command in the shell and set the vars OK, which is the problem ?

If you run a shell script it starts a new shell instance and so those exports are only going to be valid in that new instance. If you want to effect your current shell you can either do…

source script.sh
or
. source.sh

…this is different behavior from say Windows batch files.

Thanks (I put my export commands in my .profile and then all vars are ok in all shells).