Drop down list parameter

Hi

I'm trying to create a crystal report which will display a number of fields based on a user inputting a catalogue number, and then selecting the batch number (with the batch number to come from a list of batch numbers available for the chosen catalogue number)

I'm using OBTN table and fields Itemcode, Itemname, Distnumber, Notes

My first parameter prompts the user to enter a catalogue number and in select expert I have {OBTN.ItemCode} = {?Catalogue number}

For the second parameter I am getting stuck with how to get the drop down list of batch numbers associated with this catalogue number

I have tried to use "batch@SELECT DISTNUMBER From OBTN" as the name for my parameter, but I'm not getting a drop down list

Also I tried a simpler report from the crystal reports manual below:

MyParameter@SELECT * FROM OITM

http://www.pioneerb1.com/wp-content/uploads/2012/04/How-to-work-with-Crystal-Reports-8.8.pdf

But this did not give me a drop down list

My crystal reports is Basic 2008

Any help appreciated!

Thanks

Vicky