questo codice :
Dim sql As String = "SELECT * FROM dipartimenti"
Dim connection As New db_admin
Dim cmd As New MySqlDataAdapter(sql, connection.apridb)
Dim ds As DataSet = New DataSet()
cmd.Fill(ds)
rep_dipartimenti.DataSource = ds
rep_dipartimenti.DataBind()

risulta questo errore:
Overload resolution failed because no accessible 'New' can be called without a narrowing conversion:
'Public Sub New(selectCommandText As String, selectConnString As String)': Argument matching parameter 'selectConnString' narrows from 'Object' to 'String'.
'Public Sub New(selectCommandText As String, connection As MySql.Data.MySqlClient.MySqlConnection)': Argument matching parameter 'connection' narrows from 'Object' to 'MySql.Data.MySqlClient.MySqlConnection'.

in corrispondenza di questa riga:
Dim cmd As New MySqlDataAdapter(sql, connection.apridb)

qualcuno mi sa spiegare perchè?
grazie Nick