I am trying to do this as asked earlier. The only difference that I found is additional List item that was included in above code.
I tried to use AppendDataBou
AppendDataBou
DataValueField seems to be wrong - shouldn't it be DepartmentId? Similarly, you need to have SelectedValue='<%# Eval("**DepartmentId**") %>' - DepartmentName would be the SeletectText.
DataValueField
DepartmentId
SelectedValue='<%# Eval("**DepartmentId**") %>'
DepartmentName
SeletectText