writing into one line

hi
i have a file contains data

Line timeout:
START->SIGNON_REPLY,
SIGNON_REPLY->SIGNON,
Received SOT req
SOT request:
SIGNON->SOT_REPLY,
SOT_REPLY->DATA_RECEIVE,
DATA_RECEIVE->EOD,

i need to write into one line , separated by commas

please help

thanks
Satya

tr -d '\n' ' '  < inputfile > outputfile

man tr

tr '\n' ',' < file >newfile