Parse Error – HELP!

HELP! I tried to change my background color and was told I could go through the functions.php and add a specific text. Well when I did that it didn’t work, so when I went to erase it I got the following error:

Parse error: syntax error, unexpected ‘?’ in /hermes/bosweb26c/b2800/ipg.crazyforsavingscom/wp-content/themes/bueno/functions.php on line 21

I can’t access my site or the dashboard to change anything. What do I do?!