Getting Image From DB Error?

Unsure why I am getting such an error when the image is there and the
search feature for the site is not working so that doesn't help so I'm
hoping some out there can offer why I maybe getting this and help me
with getting the image from the DB.



I use the code from the starter app for retrieving an image from the DB and I get the error message:

Unable to cast object of type 'System.DBNull' to type 'System.Byte[]'



Here is the code and I am getting the error on the red line (Return New MemoryStream(CType(result, Byte()))):



Public Overloads Function GetPhoto(ByVal UserName As String) As Stream

        command.CommandText = "sp_Themes_GetUserThemeImage"

        command.Parameters.Add("@UserName", SqlDbType.VarChar, 50)

        command.Parameters(0).Value = UserName



        Dim result As Object = command.ExecuteScalar

        Try

            If result Is Nothing Then

               
Dim path As String =
HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings("siteImageDirectory"))

                path = (path + "noimageav.gif")



               
Return New FileStream(path, FileMode.Open, FileAccess.Read,
FileShare.Read)

            Else

                Return New MemoryStream(CType(result, Byte()))

            End If

        Catch e As ArgumentNullException

            Return Nothing

        End Try

    End Function



---this is the code from the imagehandler.ashx page----

Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest

       

        Dim userName As String

        Dim stream As IO.Stream = Nothing

        If ((Not (context.Request.QueryString("UserName")) Is Nothing) _

           AndAlso (context.Request.QueryString("UserName") <> "")) Then

           
userName = [Convert].ToString(context.Request.QueryString("UserName"))

            stream = (New PhotoManager).GetPhoto(userName)

       

            '
Get the photo from the database, if nothing is returned, get the
default "placeholder" photo

            'If (stream Is Nothing) Then

           
'    stream = (New PhotoManager).GetDefaultPhoto()

            'End If

            ' Write image stream to the response stream

            Dim buffersize As Integer = (1024 * 16)

            Dim buffer() As Byte = New Byte((buffersize) - 1) {}

            Dim count As Integer = stream.Read(buffer, 0, buffersize)

       

            Do While (count > 0)

               
context.Response.OutputStream.Write(buffer, 0, count)

               
count = stream.Read(buffer, 0, buffersize)

            Loop

        End If

    End Sub



---this is how I call it from the image.aspx page----



<img src='imageHandler.ashx?username=<%# Eval("UserName") %>'
style="border:2px solid white;height:40px;" alt='Thumbnail.' />



Thanks for all your help.