..try this with:
.."A>roff4 form ) "
..
.say this is a demo of form letter generation
.say "their" refers to the customer!
.PL 23
.DS .name.Ernest Bergmann.
.ds .address.Physics, Building 16.
.ds /city,state/Bethlehem, PA 18015/
J\
u\
n\
e 5\
, 1983
                                        \name
                                        \address
					Lehigh University
                                        \city,state\
.nf
\their name\
\their address\
\their city,state\

Dear \their name\,
     How are you?
                                        Sincerly,

                                        \name\