Sweet Potato Pie I

INGREDIENTS

• 1 (1 pound) sweet potato
• 1/2 cup butter, softened
• 1 cup white sugar
• 1/2 cup milk
• 2 eggs
• 1/2 teaspoon ground nutmeg
• 1/2 teaspoon ground cinnamon
• 1 teaspoon vanilla extract
• 1 (9 inch) unbaked pie crust