BPC 10.0 NW on Oracle - Checking PROMPT variable for BLANK value in logic script

Dear All,

When PROMPT values are being passed on to logic script(when a DM package is executed), say for CATEGORY DIM, how can I check if the passed value is BLANK or not? i.e.  how can I check if %CATEGORY_SET% is BLANK or not?

If this is possible, how can I check the number values, selected in the PROMPT value?

Thanks,
Peri