A DLL to modify a variable?

[Gilles G.]

Hello,
maybe I am obviously missing something, but it seems that my dll doesn't modify the value of the variables.
It looks like this:
=== File from the DLL (with the corresponding def file)
extern(Windows) void modifyThis(int* val){*val=0;}

=== call to the DLL function in the test program
alias void function(int*) modifyThis_t;
modifyThis_t modifyThis;
HMODULE h;
h = LoadLibraryA("test.dll");
int value=1;
modifyThis = cast(modifyThis_t) GetProcAddress(h,"modifyThis");
writefln("Value before call: %d",value);
(*modifyThis)(&value);
writefln("Value after call: %d",value);

But then I get the output:
Value before call: 1
Value after call: 1

I guess this is a beginner's question...
Thanks a lot!