MARSHALLTOWN PROMOTES ITSELF IN MANY WAYS, AND A NEW ONE IS ABOUT TO START.  CHAMBER OF COMMERCE TOURISM DIRECTOR ANDREW POTTER SAYS A MAGAZINE, LIFESTYLE MARSHALLTOWN, WILL DEBUT SOMETIME IN THE NEXT WEEK OR TWO.  THE VIDEO THIS IS MARSHALLTOWN WILL BE ON DISPLAY AT THE IOWA STATE FAIR WHICH GETS UNDERWAY THURSDAY.  IT WILL BE SHOWN AT THE CENTRAL IOWA TOURISM REGION BOOTH IN THE VARIED INDUSTRIES BUILDING.