Linking problem with external library

[psmallika]

Hello all
I joined newly in this forum. I recently started using dev-c++ 4.9.9.2 compiler for my c++ programs. I am presently reading c++ from c++ design by Cohoon and trying programs from it. For this I need to use a library called "ezwin" developed by the author. I have problems linking the library to my program.
here is what i had done:

step1. created a new empty project called "ezwinproject1"
step 2. in project options - parameters - linker - i added the library file (libezwin.a) from "ezwin"
in directories - libraries - i added lib folder from ezwin
in directories - include - i added include folder from ezwin
in directories - resources - i added src folder from ezwin

step 3. i wrote the following code:

code:

// project name: ezwinproject1
// filename: showstring.cpp
#include "..\ezwin\include\ezwin.h"
void display_String(char *s);
SimpleWindow sw("Hello",10,5,Position(5,5));
int WinMain()
{
         display_String("hello world");
         return 0;
}
int WinEnd()
{
 sw.Close();
 return 0;
}
void display_String(char *s)
{
  Position p1 = sw.GetCenter() - Position(2,2);
  Position p2 = sw.GetCenter() + Position(2,2);
  sw.RenderText(p1,p2,s,Red);
}

step 4. I compiled the program and i got the following errors
compiler errors:
[// project name: ezwinproject1
// filename: showstring.cpp [Linker error] undefined reference to `SimpleWindow::GetCenter() const' [Linker error] undefined reference to `SimpleWindow::RenderText(Position const&, Position const&, char const*, color const&, color const&)'
]
and so on. all these functions are defined in ezwin.cpp and is added as resource.
my question is : how can i link these functions to my project