did you add this part to code manually "<%=Request.QueryString( )%>"? this is not correct.
Do you want to filter the chart on a specific value only? or do you want to be able to different values in?
if you want to be able to pass differant values in, then you did not set the filtering up right.
If you want to pass different values in set the filter up as:
QueryString, <Enter name of the querystring variable to use>
where e<Enter name of the querystring variable to use> is the querystring variable name.
For example, if you call the page as "myPage.asp?id=3" the qurystring to use is "id"
set the filtering up as: