In A Large Mixing Bowl, Dissolve Yeast In Water. Add 1-1/2 Cups Flour, Sugar And Salt; Beat Until Smooth. Add Enough Remaining Flour To Form A Soft Dough. Turn Onto A Floured Surface; Knead Until Smooth And Elastic, About 6-8 Minutes. Place In A Greased Bowl, Turning Once To Grease Top. Cover And Let Rise In A Warm Place Until Doubled, About 1 Hour. Punch Dough Down; Press Onto The Bottom And Up The Sides Of A Greased 15-In. X 10-In. X 1-In. Baking Pan. Spread With Pizza Sauce; Sprinkle With Cheese, Ham And Pineapple. Bake At 400 Degrees F For 20-25 Minutes Or Until The Crust Is Browned And Cheese Is Melted.