DataSource Controls :: Remove Uploaded Document From Database?

I have a Document name column with varbinary(max) type column in my table

first time when i upload document i am storing doc as a byte array

Dim fs As Stream = Me.fileupload1.PostedFile.InputStream
Dim br As New BinaryReader(fs)
Dim bytes As Byte() = br.ReadBytes(fs.Length)

in my application i have remove atttachmentDoc button, i want to remove uploaded doc from db

so when i pass like this to my storedprocedue

Dim obj As New cls1
Dim bData() As Byte = New Byte(0) {}
bData=nothing
With obj
Dim dt As DataTable = Read_Doc()
If dt.Rows.Count > 0 Then
If Not IsDBNull(dt.Rows(0)("Document")) Then
.Document = bData
.Document_extension = ""
.Remove_Attachment(Me.Selected_ID)
End If
End If
End With

i got error

dbAccess.executeQuery: Procedure or function 'SP_DML1' expects parameter '@Document', which was not supplied.