io:format with multiple variables - Erlang -

i trying use following multiple parameters:

io:format("message number ~s: blah, blah", [mynum]) 

i tried:

io:format("message number ~s: ~s", [mynum, mymessage]) 

but doesn't work. possible erlang? cannot seem find examples of how this.

try:

io:format("message number ~p: ~p", [mynum, mymessage]) 

if mynum or message not strings/atoms, need use ~p