Transact SQL :: Error - No Value Given For One Or More Required Parameters

Below code gives the error "No value given for one or more required parameters"

strSQL = "insert into FILE_UPLOAD(RefNo, FileName, FileType, FileData, FileDescription, Created, CreatedBy) values "
strSQL = strSQL & "(?, ?, ?, ?, ?, ?, ?)"
Dim cmd As New OleDbCommand
cmd.Connection = objCommon.oConn
cmd.CommandText = strSQL
cmd.Parameters.Add("@RefNo", OleDbType.VarChar).Value = ""
cmd.Parameters.Add("@FileName", OleDbType.VarChar).Value = strFileName

[code]....