Summer Squash Casserole

4 small yellow summer squash, sliced
1/2 c chopped onion
1 tsp salt, divided
1 egg
4 Tbs mayonnaise
4 tsp sugar
pepper to taste
1/2 c cheddar cheese
4 Tbs crushed cornflakes
1 Tbs melted butter

In a small saucepan, combine squash, onion and 1/2 tsp salt.  Cover with water.  Bring to a boil.  reduce heat; simmer, uncovered, for 2 minutes or until squash is crisp-tender.  Drain.
In a bowl, beat the egg, mayonnaise, sugar, pepper and remaining salt until blended. Stir in cheese and squash mixture.  Transfer to greased 1 quart baking dish.  Toss the cornflakes and butter; sprinkle over the top.  Bake, uncovered, at 350 for 25 minutes or until golden brown and bubbly.  Makes 4 servings.