I have this code to get data;

 s = "select documents.filename, documents.description, documents.filesize from documents, contentdocuments, content where contentdocuments.contentid = content.id and content.id = @contentid and contentdocuments.documentsid = documents.id ORDER BY documents.description"
        x = New SqlCommand(s, c)
        x.Parameters.Add("@contentid", SqlDbType.Int)
        x.Parameters("@contentid").Value = contentid
        c.Open()
        r = x.ExecuteReader
        If r.Read Then
            DownloadsRepeater.DataSource = r
            DownloadsRepeater.DataBind()
            **imagepath = "<img src='images/'" & getimage(r("filename")) & " border='0'** align='absmiddle'"
        End If
        c.Close()
        r.Close()

The problem is on the line;

imagepath = "<img src='images/'" & getimage(r("filename")) & " 

The error is;

Invalid attempt to read when no data is present.

How can I check to make sure data is present and get rid of this error? I thought the 'if r.read' did this?

Thanks

:EDIT:

Function getimage(ByVal strin As String) As String
        If strin > "" Then
            dotpos = InStrRev(strin, ".")
            ext = Right(strin, Len(strin) - dotpos)
            getimage = ext & ".gif"
        End If
        Return getimage
    End Function