thanks you for your help.

   I did the change the ending balance , when I changed the date, and I did clear May entries when I change the date back from April to May, the Outstanding and the Unresolved still show the difference of Debit and credit of May.and when i saw the report of bank reconciliation from Apr to May, Ii shows balance.

  In my option, as long as i didn't make post, I can make any change for bank reconciliation, Am I right?

  Please tell me how can I do for next step in this situation.