after creating password for my workbook, i am not able to edit it again, and it sometimes tells me that, it is locked for editing by CRYSTAL. so please i want an adequate information about that

Go to Tools >> Protection >> Unprotect Worksheet

Enter your password.

You should be good to go.

EDIT:: If you're in Excel 2007, this option is under the Review tab of the ribbon.

That is the whole purpose of using passwords and protecting worksheets so that you cannot edit, unless you firstly unlock those cells into which you need to change data. Is Crystal the administrator on your system as it sounds like someone else is working on the sheet while you are trying to open. As long as you remember your password you can get in and unpassword it.