Hello, I am new in developing reports and I have started to use SSRS 2008 R2. Currently I am developing MDX query based report and faced an issue. I specified MDX parameter (DepartmentsDepartmentManagerFullName) default value using custom code to identify currently connected department manager: ="[Departments].[Department Manager Name].&[" +Code.GetUserFullName(User.UserID) + "]" In custom code i have wrote function witch gets current user full name and surname from active directory. If the person, witch is not manager opens report, report crashes with error: "The 'DepartmentsDepartmentManagerFullName' parameter is missing a value" So the questions are: How can perform parameter default value validation? How can i find out if default value is in avaliable values dataset and stop report from crashing? Any ideas? Thanks, Qizas