Passing parameters to SSRS from Clarion

I have a SSRS report that need 2 parameters ... I need to call it from Clarion using hyperActive template... Others reports without parameters work good but for this I'm testing the URL in IE and I got the error.. the parameters are used by stored procedure

http://server/reportserver?/Report.aspx?ItemPath=%2fFoxtel%2fCable%2fTech+Stock+Held&LocationComId=1284&DaysHeld=5

In my report I hidden the parameters, and I receive the error "The 'LocationComId' parameter is missing a value"

some idea why???

I got some answer for this question if someone need in the future from the link

http://www.mssqltips.com/sqlservertip/1336/pass-parameters-and-options-with-a-url-in-sql-reporting-services/