For Jello layers: Mix each flavor Jello in individual bowls with 1 cup boiling water. Let cool. For Filling: Mix and dissolve in saucepan the hot water and unflavored gelatin. Add sweetened condensed milk and heat over low flame. Bring to a boil, stirring occcasionally.

Let cool. Place a 9 x 13-inch clear baking pan in the freezer, leveled evenly. Pour in first flavor of jello, let set about 4 minutes, until Jello is lightly set. Pour 2/3 cup filling over set Jello, let set about 4 minutes. Repeat layers with other flavors Jello and filling. Note: Be sure jello and filling layers are cool before adding next layer!