Running Ubuntu 11.04, SDL 1.2 trying to pickup mouse wheel up/down movement with this (stripped down) code:

int main( int argc, char **argv )
{
    SDL_MouseButtonEvent *mousebutton = NULL;

    while ( !done )
    {
        if(mousebutton != NULL && mousebutton->button == SDL_BUTTON_LEFT)
            yrot += 0.75f;
        else if(mousebutton != NULL && mousebutton->button == SDL_BUTTON_RIGHT)
            yrot -= 0.75f;
        else if(mousebutton != NULL && mousebutton->button == SDL_BUTTON_WHEELUP){
            xrot += 0.75f;
        }else if(mousebutton != NULL && mousebutton->button == SDL_BUTTON_WHEELDOWN){
            xrot -= 0.75f;
        }

        while ( SDL_PollEvent( &event ) )
        {
            switch( event.type )
            {
                case SDL_MOUSEBUTTONDOWN:
                    mousebutton = &event.button; 
                    break;
                case SDL_MOUSEBUTTONUP:
                    mousebutton = NULL;
                    break;
                default:
                    break;
             }
        }
    }
    return 0;
}

strange thing is, scrolling with the mouse button does nothing, but if I hold down a mouse button or two and then move the mouse it hits the SDL_BUTTON_WHEEL code occasionally. This honestly reeks of a pointer issue, which would make sense since I've been spoiled with C# for the past couple years, but I am just not seeing it.

How do i correctly find mouse scroll events in SDL?