can some one help me with writing a letter for notarization?

[sweetz123]

im writing a letter stating that i am able to receive collect calls from an inmate that i guess i must have put that i wasn't gonna allow collect calls from him when i sent out the visitation application.but i am actually able to and in order to change this i must send a notarized letter to them stating i allow then but how do i write the letter? and how long does it have to be? can some one help me with this?! its important for me to keep communication going between my son and his father and i would really appreciate the help.thanx