Sefid, I'm not certain but it looks to me from the error message you posted you need something more akin to
" ./exrun resetdb
<the name of the db you'd like to reset here> -u root -p psswrd"
Of course, I know exactly as much about mysql as I need to do my non-dba job, and even less about mysql++ so actual mileage may vary, read all directions and be sure to consult a physician before... well, you get the picture...
Hope that helps