Thin Cheese Sauce

1 1/4 cups grated cheese
2 teaspoons salt
2 teaspoons vetsin
1 cup water
1/2 cup milk, evaporated
2 tablespoons flour
2 tablespoons margarine

Melt margarine in low fire, add flour. Add salt, vetsin and cheese. While stirring, slowly add water and milk. Continue stirring until smooth.