Legend for GPResultImageLayer

[IgressT]

Hi,
In my previous post I was trying to create a GP task with a Result Map Service
http://forums.arcgis.com/threads/22613-GPResultImageLayer-No-Image?highlight=GPResultImageLayer

I was successful in creating the GP task and when I execute the GP task in my silverlight app I get back the result as an image and an able to add it to the map.

How to get the legend?