pass a value to a dll under labview

[/*draven*/]

I have to build a dll under cvi and use it under labview.  my problem
is to pass a value to this dll from labview.
But when I use it, labview return an error code  and close the
software...
I can return value from the dll to labwiew but not the contrary. can
you help me please.
 I am a beginner and I am sorry for my english...