In large saucepan, combine soup, mayonnaise, sour cream and onion. Stir in chicken, water chestnuts, broccoli and celery. Cook over medium heat until mix is hot and bubbly. Pour into ungreased 13x9 inch baking dish. Unroll the crescent roll dough and separate into two rectangles, trimming to fit dish. Place dough rectangles over hot chicken mixture. Combine cheese and almonds; sprinkle over dough. Drizzle with butter. Bake at 375F for 20-25 minutes or until crust is deep golden brown. Serve immediately. Serves 8.