OpenGL's glReadPixels problem (boundary fill)

Code:
#include "stdafx.h"

#include <GL/glut.h>



using namespace System;

struct Color

{

    float red, green, blue;

    bool equals(Color color)

    {

        if (color.red == red && color.green == green && color.blue == blue)

            return true;

        else return false;

    }

    void getColor(int x, int y)

    {

        float temp[3];

        glReadPixels(x, y, 1, 1, GL_RGB, GL_FLOAT, temp);<--------[B] this[/B]

        red = temp[0];

        green = temp[1];

        blue = temp[2];

    }

    void paint(int x, int y)

    {

        glBegin(GL_POINTS);

        glColor3f(red, green, blue);

        glVertex2i(x, y);

        glEnd();

    }

};

void boundaryFill4(int x, int y, Color colorToFill, Color borderColor)

{

    Color temp;

    temp.getColor(x, y);

    if (!(temp.equals(colorToFill) || temp.equals(borderColor)))

    {

        colorToFill.paint(x, y);

        if (x < 200) boundaryFill4(x+1, y, colorToFill, borderColor);

        if (x > 0) boundaryFill4(x-1, y, colorToFill, borderColor);

        if (y < 200)boundaryFill4(x, y+1, colorToFill, borderColor);

        if (y > 0) boundaryFill4(x, y-1, colorToFill, borderColor);

    }

}

void myDisplay()

{

    glClear(GL_COLOR_BUFFER_BIT);    

    Color boundColor;

    boundColor.red = 1;

    boundColor.green = 1;

    boundColor.blue = 1;

    glColor3f(boundColor.red, boundColor.green, boundColor.blue);

    glBegin(GL_LINE_LOOP);

    glVertex2i(100, 100);

    glVertex2i(100, 150);

    glVertex2i(150, 150);

    glVertex2i(150, 100);

    glEnd(); 

    Color colorToFill;

    colorToFill.red = 1;

    colorToFill.green= 0;

    colorToFill.blue = 0;

    boundaryFill4(120, 120, colorToFill, boundColor);

    glFlush();

}

void initializeGL()

{

    glClearColor(0.0, 0, 0, 1.0);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    gluOrtho2D(0.0, 200.0, 200.0, 0.0);

}

int main(int argc, char** argv)

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB);

    glutInitWindowSize(500, 500);

    glutInitWindowPosition(0,0);

    glutCreateWindow("My Rectangle");

    glutDisplayFunc(myDisplay);

    initializeGL();

    glutMainLoop();

    return 0;

}