contra entry means it is treats in cash book and pass book
two times

two conditions is apply this entry namely:


1. cash depositted into bank  for office useand
         cash a/c    Dr
           to Bank a/c

2. cash with draw from bank for office use......

          Bank a/c       Dr
               cash a/c.

two types of conta entry 
1. cash deposit into the bank
bank a/c dr
   to cash a/c

2. cash withdraw from bank
cash a/c .d/r
   to bank a/c

When Cash withdrawn from Bank
Cash A/c ........Dr
To Bank A/c

When Cash Deposited into Bank
Bank A/c.........Dr
To Cash A/c