Using a dll function

Hi all. I'm sorta new to JNI and I had a question. I have a pre-existing dll called "mydll.dll" and its header file "mydll.h"
I am trying to access a funtion " int GetVersion() " using JNI.
I have written the following C funtion to access the function in the dll
JNIEXPORT jint JNICALL
Java_myApp_GetVersion(JNIEnv *env, jobject obj)
jint myInt;
myInt = (*env)->GetWrapperVersion();
return myInt;
However, when I try to compile this I get the following error
Error E2451 : Undefined symbol 'GetVersion' in function Java_myApp_GetWrapperVersion
What am i doing wrong here? Is this the correct way to call the function? Or is the problem caused because of the location of "mydll.dll". Right now it is in the same directory as the C file and the Java classes.
Thanks for your help.
Vinny.

also, the function in "mydll.h" is defined as
int __declspec(dllexport) GetVersion ();
I am using Borland C++ 5.

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qing_shan61 wrote:
When I use Call Library Function Node in real time, is the DLL loaded once for all or load every time when it is called?
Once
qing_shan61 wrote:
I have a time critical real time application, in which I use a piece of DLL function developed by C++. It is OK?
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