Query parameter not found while run report

Hello,
With the report create wizard I created a report to generate an excel report. So far so good, its a list of entities with a query. The query looks so far normal,

select
...
where (e.workday<= :enddate and e.workday>= :startdate)

The parameter enddate and startdate I defined as parameters in the “parameters and formats”-Tab. When I run the report I got a dialog box asking me for parameters. But as soon as I set the values and Run the report I got an error message:

"An error occurred while loading data for data set [Dataset]
Query argument enddate not found in the list of parameters provided during query execution."

I could not find what is wrong, somehow the parameters could not get detected while execution of the query, any ideas or hint?

Thank you very much

Hans-Juergen

You should define parameters in the query in the following form: ${enddate}, ${startdate}.

See examples in the docs.