Convert c++ float to jfloat???

Hi,
I'm trying to get a float value from my C++ program to Java. I'm creating the float variable in eVC++ and doing some calculation with that and then want to return the float in java. But I always get the value of float variable in Java is 0.0. And I also can't check the value of 'width' in eVC++. How can I print the value of float in a messagebox in eVC++ or in Java console from C++ program? How can I get the C++ float value to Java? The C++ code -
JNIEXPORT jfloat JNICALL Java_packageName_ClassName_methodName(JNIEnv *env, jobject, jstring jStr) {
float width;
doing something with width
return width;
}Any idea???
thanx

1) Does this code compile without warnings? You have this signature:
JNIEXPORT jfloat JNICALL Java_packageName_ClassName_methodName(JNIEnv *env, jobject, jstring jStr)yet you return a float value...
2) What is the output if you run with java -Xcheck:jni [... other args ...] yourClass

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