[MS office Help(Improper functioning )]

dear sir,

Any thing i try to write into the document it is flashing me
a message that "this documenttation is not allowed because the document is
locked" . hence i request you to suggest me quickest possilble solution to
get rid of this problem.
I am a ms office user with version office12 .

Thanking you,

Shaik.Moulali