File format is invalid for .rtf format

Hi all,

        Currently i am working on VSTO with C#.net. I am having a form where i am have one DropDownList and a RichTextBox.
When I select an item in the list, the xmldata(tags)from the database has to be shown in RichTextBox.

       Here is the code snippet:

                                       rtbReuseData.Rtf= xElement.Element(DropDown.Value).Value;
       
        Now, when i am selecting an item from the DropDownList, it is showing an error "File format is Not valid". (When i take the .text instead of .rtf, it is showing some data but is not of format.)I want to show xml format data in the Richtextbox.

        Please help me in getting this problem solved.
 
        Thanks,
        K.S.Reddi Prasad.