Segmentation Fault

[noey699]

#include <allegro.h>

BITMAP *RedBlock;
BITMAP *BlueBlock;
BITMAP *WhiteBlock;
BITMAP *GreenBlock;
BITMAP *BlackBlock;
BITMAP *Background;
BITMAP *Background2;
BITMAP *buffer;
//BlockColor 0 = no block 1 = redblock 2 = blueblock 3 = whiteblock 4 = greenblock
int BlockColor[15][17] = {{0},{0}};
int color;
int BlockPosX [15];
int BlockPosY [17];
int CounterPos = 0;
void NewGame(){

}
int MoveSingleBlock( int Blockx, int Blocky, int color1 ){
    if ( color1 == 1 ){
        draw_sprite( Background2, BlackBlock, BlockPosX[Blockx], BlockPosY[Blocky] );
        draw_sprite( Background2, RedBlock, BlockPosX[Blockx], BlockPosY[Blocky - 1]);
    }
    if ( color1 == 2 ){
        draw_sprite( Background2, BlackBlock, BlockPosX[Blockx], BlockPosY[Blocky] );
        draw_sprite( Background2, BlueBlock, BlockPosX[Blockx], BlockPosY[Blocky - 1]);
    }
    if ( color1 == 3 ){
        draw_sprite( Background2, BlackBlock, BlockPosX[Blockx], BlockPosY[Blocky] );
        draw_sprite( Background2, WhiteBlock, BlockPosX[Blockx], BlockPosY[Blocky - 1]);
    }
    if ( color1 == 4 ){
        draw_sprite( Background2, BlackBlock, BlockPosX[Blockx], BlockPosY[Blocky] );
        draw_sprite( Background2, GreenBlock, BlockPosX[Blockx], BlockPosY[Blocky - 1]);
    }
}
void MoveBlocks(){
    int x = 17;
    int i = 0;
    while ( x != 0 ){
        while( i != 15 ){
            if (BlockColor[i][x - 1] == 0 ){
                MoveSingleBlock(BlockPosX[i], BlockPosY[x], BlockColor[i][x]);
            }
            i = i + 1;
        }
        x = x - 1;
}
}
void SetBlockPos(){
   BlockPosX[0] = 122;
   BlockPosX[1] = 148;
   BlockPosX[2] = 174;
   BlockPosX[3] = 200;
   BlockPosX[4] = 226;
   BlockPosX[5] = 252;
   BlockPosX[6] = 278;
   BlockPosX[7] = 304;
   BlockPosX[8] = 330;
   BlockPosX[9] = 356;
   BlockPosX[10] = 382;
   BlockPosX[11] = 408;
   BlockPosX[12] = 434;
   BlockPosX[13] = 460;
   BlockPosX[14] = 486;

   BlockPosY[0] = 455;
   BlockPosY[1] = 429;
   BlockPosY[2] = 403;
   BlockPosY[3] = 377;
   BlockPosY[4] = 351;
   BlockPosY[5] = 325;
   BlockPosY[6] = 299;
   BlockPosY[7] = 273;
   BlockPosY[8] = 247;
   BlockPosY[9] = 221;
   BlockPosY[10] = 195;
   BlockPosY[11] = 169;
   BlockPosY[12] = 143;
   BlockPosY[13] = 117;
   BlockPosY[14] = 91;
   BlockPosY[15] = 65;
   BlockPosY[16] = 39;


}
void newline(){

    int i = 0;
    while (i != 15){
        color = rand()&#37;4;
    if (color == 0){

        draw_sprite(Background2, RedBlock, BlockPosX[i], BlockPosY[16]);
        BlockColor[i][17] = 1;
        i = i + 1;

    }
    if (color == 1){

        draw_sprite(Background2, BlueBlock, BlockPosX[i], BlockPosY[16]);
        BlockColor[i][17] = 2;   //i believe this is line 103
        i = i + 1;

    }
    if (color == 2){

        draw_sprite(Background2, WhiteBlock, BlockPosX[i], BlockPosY[16]);
        BlockColor[i][17] = 3;     
        i = i + 1;

    }
    if (color == 3){

        draw_sprite(Background2, GreenBlock, BlockPosX[i], BlockPosY[16]);
        BlockColor[i][17] = 4;
        i = i + 1;

    }
}
}



int main(){
    //initialize allegro
    allegro_init();
    install_timer();
    install_keyboard();
    install_mouse();
    srand(time(NULL));
    set_color_depth(16);
    set_gfx_mode( GFX_AUTODETECT, 640, 480, 0, 0);
    //set the block positions
    SetBlockPos();
    //load needed bitmaps
    buffer = create_bitmap( SCREEN_W, SCREEN_H );
    Background2 = create_bitmap( SCREEN_W, SCREEN_H );
    Background = load_bitmap( "background.bmp", NULL);
    RedBlock = load_bitmap( "redblock.bmp", NULL);
    WhiteBlock = load_bitmap( "whiteblock.bmp", NULL);
    BlueBlock = load_bitmap( "blueblock.bmp", NULL);
    GreenBlock = load_bitmap( "greenblock.bmp", NULL);
    BlackBlock = load_bitmap( "blackblock.bmp", NULL);
    //newline and MoveBlocks timer
    install_int_ex(newline, SECS_TO_TIMER(5));
    install_int_ex(MoveBlocks, MSEC_TO_TIMER(50));
    //make a background i can draw on
    draw_sprite(Background2, Background, 0, 0);
    //main game loop
    while ( !key[KEY_ESC] ){
    //acquire screen for writing
    acquire_screen();
    //draw the background to buffer

    draw_sprite(buffer, Background2, 0, 0);

    //release screen
    release_screen();
    blit(buffer, screen, 0, 0, 0, 0, SCREEN_W, SCREEN_H);
    rest(80);
    }

    return 0;

}
END_OF_MAIN();

I cannot figure out where this error is coming from. This is my first full game, so forgive me if it is sloppy at all but I would really appreciate it if you could help me with this problem ASAP. I am using Allegro which already declares all the include files needed for C++. The error always points at line 103, I have the line marked with a comment. Thank you in advanced.

also my operating system is vista

[PredicateNormative]

Look at your declaration of BlockColor:

int BlockColor[15][17] = {{0},{0}};

What is the maximum index you can use (i.e. what index values would you use to access the last element in the array)?

Now look at the line in question (and all the other lines that access BlockColor in the function for that matter).

BlockColor[i][17] = 2;

What do you notice? The maximum index is BlockColor[14][16], you have gone beyond that, and that is why you have a segmentation fault.