Parameter with Number data type

Hi All,

I am creating a report with a paramater "AccountID" and the date type is number.

I want the user to enter "99999" if they want to pull out all the "AccountID".

(if {?AccountID} = 99999 then True

else

{AR041_ATB.AccountID} = {?AccountID})

It always give me an empty report when I enter "99999".

Please help.

Thanks