Undefined reference to template members

I'm new to C++, and preparing a homework by using NetBeans IDE on Ubuntu 10.04. I use g++ as a C++ compiler. The error message: ``` build/Debug/GNU-Linux-x86/Maze.o: In function `Maze': Maze/Maze.cpp:14: undefined reference to `Stack<Coordinate>::Stack()' Maze/Maze.cpp:14: undefined reference to `Stack<Coordinate>::Stack()' Maze/Maze.cpp:69: undefined reference to `Stack<Coordinate>::push(Coordinate)' Maze/Maze.cpp:79: undefined reference to `Stack<Coordinate>::isEmpty()' Maze/Maze.cpp:87: undefined reference to `Stack<Coordinate>::destroy()' ``` And my related code: Maze.h ``` #include "Coordinate.h" #include "Stack.h" .... .... /** * Contains the stack object * * @var Stack stack * @access private */ Stack<Coordinate> *stack; ... ... ``` Maze.cpp ``` #include "Maze.h" ... ... Maze::Maze() { // IT SHOWS THAT THE FOLLOWING LINE HAS AN ERROR/// stack = new Stack<Coordinate>; /////////////////////////////////////////////////// for( int y=0; y<8; y++ ) { for( int x=0; x<8; x++ ) { maze[y][x] = '0'; } } } ... ... ``` And according to the error output, Each line that I used stack variable has an error: Undefined reference. Stack.cpp ``` #include "Stack.h" ... ... template <class T> Stack<T>::Stack() { // Create the stac! create(); } ... ``` I have googled it, but could not solve the problem. I think there is something wrong with my includes order, or maybe I used the pointers in a wrong way. I also tried to create a makefile by myself, but the result did not change. I prepared this makefile according to this link: http://www.cs.umd.edu/class/spring2002/cmsc214/Tutorial/makefile.html Here is my makefile: ``` maze: Maze.o Stack.o Coordinate.o g++ -Wall Maze.o Stack.o Coordinate.o -o maze Maze.o: Maze.cpp Maze.h Stack.h Coordinate.h g++ -Wall -c Maze.cpp Stack.o: Stack.cpp Stack.h g++ -Wall -c Stack.cpp Coordinate.o: Coordinate.cpp Coordinate.h g++ -Wall -c Coordinate.cpp Maze.h: Stack.h Coordinate.h ``` How could I overcome this error? Any ideas?