help with pong.

below is my code for pong that i am currently working on but have come to a bit of a dead end i cant firgure out how to write collision for my code any advice or sample code would be nice have fun reading i tried to keep my code neat.

// SDL_App.cpp : Defines the entry point for our Project
//
//#include "stdafx.h"
#include <Windows.h>
#include "GL_Functions.h"
#include "pctimer.h"
#include <string>
#include <cmath>

#include <crtdbg.h>

// theme of project is pong from a metroid perspective
//{ make this a function later =D

    enum STATE
    {
      MAINMENU,  // will take user to main menu at start of game or during
      SINGLEPLAYER,  // one player mode
      MULTIPLAYER, // player vs player mode
      HIGHSCORES, //lists high score
      OPTIONS, // opens the options menu
      QUIT // when user presses escape key program closes
    };








int main(int argc, char* argv[])
{

    //Lets open the window and initialise opengl
    InitGL(1024,768);
    int background = LoadTexture ("./images/background.png");
    int mball = LoadTexture ("./images/mball.png");
    int leftpaddle_2 = LoadTexture ("./images/paddle_2.png");
    int rightpaddle_1 = LoadTexture ("./images/paddle_1.png");
    //int Menu = LoadTexture ("./images/MENU.png");

    //stuff to complete.......!!!!
    //STATE currentstate;

    //bool singeplayer()

        //{
            //currentState = MAINMENU
            //while(bContinueGame)
            //{
                //case
    //}
    float backgroundx = 0;
    float backgroundy = 0;
    float mballx = 492; // 'M' stand for metroid.
    float mbally = 384;
    float ballxspeed = 4;
    float ballyspeed = 2;
    float rightpaddle_1x = 990;
    float rightpaddle_1y = 20;
    float leftpaddle_2x = 15;
    float leftpaddle_2y = 450;
    float ballrside = mballx + 40;
    float position = 0;
    float paddle_width = 5;
    float paddle_length = 15;
    float ball_width = 2.5;
    float ball_length = 5;

    //while true()
    //{ make this a function later =D
    //  enum STATE
    //  MAINMENU  // will take user to main menu at start of game or during
    //  SINGLEPLAYER   // one player mode
    //  MULTIPLAYER  // player vs player mode
    //  HIGHSCORES  //lists high score
    //  OPTIONS // opens the options menu
    //  QUIT  // when user selects 'quit' program closes
    //}


     do
    {
        //Clear the screen, so previous frames don't build up
        ClearScreen();

        mballx = mballx + ballxspeed;
        mbally = mbally + ballyspeed;


//////////draws images to screen////////////////////////////////////////////////////
        DrawSprite(background, backgroundx, backgroundy, 1024, 768);  //////////////
        DrawLine(512,0,512,768);                                      //////////////
        DrawSprite(mball, mballx, mbally, 40, 40);                    //////////////
        DrawSprite(leftpaddle_2, leftpaddle_2x,  leftpaddle_2y, 20, 100); //////////
        DrawSprite(rightpaddle_1, rightpaddle_1x, rightpaddle_1y, 20, 100); ////////
////////////////////////////////////////////////////////////////////////////////////


        //highscores
        //{
        //  int iHighscore[6}
        //  int iScore = 0
        //  char scorestring[] = "score"
        //  while (iscore < 6)
        //  printf("Highscore: %i %i/n"), (iScore+1), iHighscore[iScore]);
        //  ++iScore;
        //   for{
        //     (int iHighscore = 0;, iHighscore < 10, iHighscore++)
        //  printf(
        //  }
        //}


        // ball speed/control
        //
        if (mballx > 984)
        {
            mballx = 492;
            mbally = 384;
            ballxspeed *= -1;
        }

        if ( mballx < 0)
        {
            mballx = 492;
            mbally = 384;
            ballxspeed *= -1;
        }

        if (mbally > 1024 || mbally < 0)
                ballyspeed *= -.5;

        // controls for players one and two
        // player one's controls ( 'w' and 's')
        // player two's controls ( 'up' and 'down')


        if (IsKeyDown(KEY_UP))
        {
            rightpaddle_1y = rightpaddle_1y -5;
            if( rightpaddle_1y < 0 )
            {
                rightpaddle_1y = 0;
            }
        }

        if (IsKeyDown(KEY_DOWN) && rightpaddle_1 < 668)
            rightpaddle_1y = rightpaddle_1y +5;

        if (IsKeyDown('w') && leftpaddle_2 > 0)
            leftpaddle_2y = leftpaddle_2y -5;

        if (IsKeyDown('s') && leftpaddle_2 < 668)
            leftpaddle_2y = leftpaddle_2y +5;

        // closes program down atfer user presses escape!
        if (IsKeyDown(KEY_ESCAPE))
            CloseDown();


        //limit paddles so that stay with in boundaries placed
        // well they would if i could program
        {
        if(leftpaddle_2y < 0)
            leftpaddle_2y = 0;

        if(leftpaddle_2y + paddle_width > 668)
            leftpaddle_2y = 668 - paddle_width;

        if(rightpaddle_1y + paddle_width > 668)
           rightpaddle_1y = 668 - paddle_width;
        }
        //ball impact values below
        //makes ball go bouncy bouncy
        //ball collision should be here....
        {
        if(ball_length + ball_width > paddle_width + paddle_length)
        mballx,mbally = 0;

        // these do stuff
        // without them game crashes....
        if(mballx > rightpaddle_1x + rightpaddle_1y)

        if(mballx = leftpaddle_2x - position && leftpaddle_2y > ball_width)

        if(mbally = rightpaddle_1x + position && rightpaddle_1x > ball_width)
        return(0);
        }
        //Stop it from running too fast! Sleep ZZzzz
        Sleep(5);

        } while (FrameworkUpdate()); //Do some secret stuff,


        FreeTexture(leftpaddle_2);
        FreeTexture(rightpaddle_1);
        FreeTexture(background);
        FreeTexture(mball);



        //Close down
        CloseDown();

        _CrtDumpMemoryLeaks();

        //Quit!
        return 0;
 }