Per the reference, client.command_text is outmoded and should no longer be used unless you're intent on using the default skin. For users creating their own skin, it's better to set the input control's command parameter to something like "!defaultverb", where the ! goes in front of the command.
// an example of how to do this at runtime var/params = list("command" = "!say \"") winset(usr, "input", list2params(params))