Prompts in Universe based on Stored Procedure

Hello All,

I have a universe based on stored procedure. There are two prompts "Date from" and "Dateto" which I set up as "prompt me a for a new value" in the universe.

When I run the webi report it prompts me to enter the date range. I enter and run the report, but when I refresh the report the dates that were selected before shows up in the prompt window(last values selected). How do I make it in a way that when I refresh the report the values are blank i.e it doesnt have the last values selected?

I have saved the report as refresh on open but how do I avoid the prompt values?

Thanks,

Nisha