Display custom Error Message

[naveen_hadagali]

 In Cognos 8,I have a report, which has the "select  & search prompt" prompt for material.  And, it has many records for material drop down list, and, when the report is run with the option of "select all" for material start with 06%.  Then, the number of rows for material is over 3000 records, &, the report will errored out  And, in the error log, the error will be as follow:
"oracle-01795: maximum number of expressions in the list is 1000".

I want to show a error message if the user selects more then 1000 values and ask to reselect the propt values less then 1000. Any suggestions and views are highly appreciated. Its urgent

Regards
Naveen