SQL Server Reporting Services 2005 - 如何隐藏图表的图例标签？

I am reporting on data that lets say has 10 columns. Now some of my clients have data in all 10 of the columns whereas some may only use 7 or 5... you get the idea. Of course I dont want to have to build a new rdl for each possibiliy. Well in the tabular report I can hide the columns fine if no data exists by using the IsMissing property.I am reporting on data that lets say has 10 col