Global instance error.

[Musi]

I've been trying to create a global instance of a class but when i use it i get an "Unresolved external symbol" error and i can't figure out why. This is how it's set up.

MyClass.h

#ifndef MYCLASS_H
#define MYCLASS_H

class MyClass
{
public:
	void func();
};

#endif 

MyClass.cpp

#include "MyClass.h"

void MyClass::func()
{
	int x = 1;
}

Global.h

#ifndef GLOBAL_H
#define GLOBAL_H

#include "MyClass.h"

namespace Global
{
	extern MyClass g_myClass;
}

#endif 

Global.cpp

#include "Global.h"

namespace Global
{
	MyClass g_MyClass;
}

main.cpp

#include "Global.h"

int main()
{
	Global::g_myClass.func();
	return 0;
}

Everything is fine until i try to call func() then i get this error,
LNK2001: unresolved external symbol "class MyClass Global::g_myClass"

Anyone know what i'm doing wrong? Thank you

[LB]

Is Global.cpp being compiled? It needs to be part of the project.