How can I check if a variable has some sort of text in it like hello...

Example:
I've got a guestbook, and I want to check if the text says , , and further on..
I've already checked if ($variable eq ' ')
but ofcourse that's not the option.

Neway I'm searching for a way to add smilies cause I am almost finished with a guestbook..

Thank you

$code = ':)';

$text =~ s,Q$codeE,,isg;