Here is what I did. 1.) Created a report parameter and selected multivaue parameter and passed the assigned dataset to the available values in the from query. 2.) In the preview mode I was able to see a list box with the ckeck boxes and NOT select All because I am using SP1. Here is the problem I am facing.. 1.) We are calling all our reports through Windows forms application using ReportingServices2005 webservices. 2.) For this perticular report because we have opted for Multivalue we are creating a dynamic listbox with the MultiSelect option. 3.) By using the ValidValues property we are filling the list box in the report and using the listbox for selecting the selected items. 4.) We are passing comma seperated Selected items to a parameter called X. 5.) When we press display report button it says "The parameter X is missing a value " but when I see in the quick window it has all the selected items passed as comma seperated ("test,user,waste") to the parameter X. My question is : Does the Webservices identify Comma seperator for a passed parameter OR Please help me fix this problem.