S' more bars

1 cube butter
1 lg pkg marshmallows
7 C. golden grahams cereal
1 pkg. chocolate chips

Melt butter and marshmallows in microwave( stir every 30 seconds takes about two minutes.) Stir in cereal.  Let cool a bit then stir in chocolate chips.  Press into lightly greased 9x13 pan.   cool and serve.  someone said they like to refrigerate  them and serve them cold.