I have an enetity set on a page linked to a gridview showing a list of holidays. I also have a gauge on the same page. I want to be able to bind the gauge to the same datasource/datacontext and produce a show a SUM value of all the holidays. Therefore as they add new holidays to the grid the gauge would then increase/decrease its value. I have seen how you can bind it to a value but not to take an entity set and produce the SUM value. Thanks P