[thelist] type DataListCommandEventArgs is not defined

[Casey Crookston]

I'm trying to edit an item in a datalist:

Sub dtlPhotos_EditCommand(ByVal s As Object, ByVal e As
DataListCommandEventArgs)
	'fubar
End sub

I'm told: type 'DataListCommandEventArgs' is not defined

It already Imports System.Data.SqlClient - anything else I need to do?

Thanks!