Help me define next() fuction in HANGMAN [fltk]

[Der_sed]

How should I define the next() fucntion- LINE 69.

For now the get_string isnt even fetching the string from the In_box

//09030032 at lums

//======================================
//Stroustrup Interface Libray files
//======================================
#include "Simple_window.h"   
#include "Graph.h"
#include "GUI.h"
#include "Window.h"
#include "../std_lib_facilities.h"  
//======================================
//Load neccessary header files
//======================================
#include <fstream>                //to load words from file
#include <sstream>                //for text
#include <iostream>               //to use getline function
#include <vector>                 //to save word and hint list
#include <cstdlib>                //for rand();
#include <cstring>
using namespace std;
using namespace Graph_lib;




//////////////////////////////////////////////////////////////////////
//HANG MAN WINDOW CLASS
/////////////////////////////////////////////////////////////////////

struct Hangman_window : Window {
   
    Button next_button;        // Input word
    Button quit_button;
    In_box next_x;
    
    ////////////////////////////////////////////////////////////////////////
    //CONSTRUCTOR: create window, quit button, next button
    ////////////////////////////////////////////////////////////////////////

    Hangman_window(Point xy, int w, int h, const string& title,Image& background)
                         :Window(xy,w,h,title),
                         next_button(  Point(200,y_max()-50)          , 70, 20, "Enter", cb_next),
                         quit_button(  Point(x_max()-100,y_max()-50), 70, 20, "Quit", cb_quit),
                         next_x(Point(100,y_max()-50), 50, 20, "Guess a letter:")
    
    { 
      attach(background);
      attach(next_button);
      attach(quit_button);
      attach(next_x);}
    //////////////////////////////////////////////////////////////////////
    
    
    
    
  
    
    ///////////////////////////////////////////////////////////////////////////
    void quit()                           
    { hide();}
     
    static void cb_quit(Address, Address pw)    // callback for quit_button
         { reference_to<Hangman_window>(pw).quit();}
    ////////////////////////////////////////////////////////////////////////////  


    static void cb_next(Address, Address pw)     // callback for next_button
    {reference_to<Hangman_window>(pw).next();} 
    
    
void next()
    {
        
          string str=next_x.get_string(); }
          
/*        char c=s[0];
          Text t(Point(640,480), s);
          attach(t);
          redraw(); 


    CHECK IF LETTER IS IN THE STRING
DISPLAY IF IT IS.
OR ELSE RECEDE MASK !!!!!!!!!!

      redraw(); 
*/         
           
         
     






};     



//========================================================================
// Draw spaces/blanks
//========================================================================
void drawSpaces ( Hangman_window& win, int num, Lines& LX)
{    int x=10, y=400;
     for (int f=0; f<num; f++)
     {   LX.add(  Point(x,y),Point(x+50,y)  );
         x=x+60;}
     
     
     win.attach(LX);
     }
//========================================================================


int main ()
{
    
    
    //**************************************************************************
    //create a 1024*768 window with a white background
    Point tl(100,100);
    Image bkgrnd(Point(0,0),"background.jpg");  
    Hangman_window win (tl,1024,768,"Canvas",bkgrnd);
    
    //**************************************************************************
    
    
    
    //Instructions & Credits
    Text t1(Point(700,20), "Hangman v1.0 - created by __________ Inc.");
    Text t2(Point(50,50), "Guess the word, before you're hanged to death. Enter a letter in the box");
    t2.set_color(Color::blue);
    Rectangle box(Point(30,20),600,40);
    win.attach(box);
    win.attach(t1);
    win.attach(t2);
    
    
    
    //Hangman Guy comes in the Window
    int mask=50;            //value by which mask will recede (a 50 pixel drop down)
    Image alive(Point(700,50),"alive.jpg");
    alive.set_mask(Point(0,0),570,mask); 
    win.attach(alive);



    //***************************************************************************
    //Load word list and hints into vectors. Then choose a word to use in the game.
    //***************************************************************************
    vector<string> words;
    vector<string> hints;
    ifstream readfile("hint_wordlist.txt");  //open file
   
    while (!readfile.eof())                  //loop to load hints and words into their vectors
    {     string s;
          getline(readfile,s,'\n');
          words.push_back(s);
          getline(readfile,s,'\n');
          hints.push_back(s);
          } readfile.close();                //close file
     
     string word;                            //randomly chosen word to use in game
     string hint;                            //along with its hint
     int random;     
     do                                      //loop to randomly choose the right word for the game
     {      
            random=rand();
            if (random<words.size())
            { word=words[random];
              hint=hints[random];}
            } while ( random<words.size() );  
   

    //***************************************************************************
    //Draw Spaces/Blanks
    //***************************************************************************
    Lines LX;
    drawSpaces(win,word.size(),LX);
    //***************************************************************************
    
    
  








    return gui_main();
}