How new number should come on new screen while clicking on createnewproduct link

How new number should come on new screen while clicking on createnewproduct link

  
Hi All,

 followed the step that i written a query on the product, order by product in descending
Took the first record  (list.current.product.id) and add 1 to it and that will be my new number   but  at run time in new screen  It's not showing the number.

Could any one  Please give me example
This is the same question as http://www.outsystems.com/NetworkForums/ViewTopic.aspx?TopicId=8994&Topic=auto-generate-number-