Vegetable Lasagna

In nonstick 12-inch skillet, melt 1 tablespoon butter or margarine over medium heat. Add zucchini, broccoli, oregano, and 1/4 teaspoon salt and cook, stirring frequently, until vegetables are tender-crisp, about 5 minutes. Add spinach and toss until wilted. Remove skillet from heat. In medium bowl, mix ricotta and eggs; set aside. In large saucepot, prepare lasagna noodles in boiling salted water as label directs. Drain. Meanwhile, preheat oven to 350F. In 2-quart saucepan, melt remaining 3 tablespoons butter or margarine over medium heat. Stir in flour and 1/4 teaspoon salt until smooth. Gradually stir in milk; cook, stirring constantly, until sauce boils and thickens. Remove saucepan from heat; stir in Parmesan. In 13 x 9-inch glass baking dish, layer half of lasagna noodles, half of ricotta mixture, half of vegetable mixture, and half of Mozzarella. Top with half of white sauce, then with remaining noodles, ricotta, and vegetable mixture. Spoon remaining sauce over vegetable layer; arrange remaining Mozzarella on top. Bake lasagna 40 to 45 minutes or until hot and bubbly.