No such column exception in Android SQLite Database while selecting rows

I am working with android SQLite database. I am getting SQLLite exception as 'Caused by:android.database.sqllite.SQLITEException:no such column DD(code 1):, while compiling :SELECT _id, sms, contact, time FROM messages WHERE contact =DD-Aircel ORDER BY _id DESC ' while selecting rows having contact as DD-Aircel (not while inserting the same). I think it is due to hyphen '-' in DD-Aircel. Datatype of column contact is STRING. Can any1 plz explain with the solution. Thanks in advance .