System.Exception: This page has a MM:DataSet, MM:Insert, MM:Update or MM:Delete tag with a null or empty value for the ConnectionString attribute. 

Often, such values come from application settings in the web.config file. That file might be missing from the server executing this page. Or, it might be missing the particular add key tags for the database connection this page uses. If you are using Dreamweaver, look for the web.config file in the local root folder of your Dreamweaver site. Once you find this file, you can either:
Put this file onto the server that is executing this page.
Copy the add key tags from the web.config in the local root folder of your Dreamweaver site and paste them into the web.config file in the server that is executing this page.

at DreamweaverCtrls.DataSet.DoInit()

<script runat="server">
     Sub Popola_datagrid(Src As Object, E As EventArgs)
   
         Dim Connessione As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=percorsofisico\database.mdb") 
      'Connessione.Open() 
      Dim sql As String 
      Dim cmd As New OleDbDataAdapter("SELECT TblInt.IntKey, TblCol.ColNom, TblDep.DepCom, TblInt.IntDat, TblInt.IntEse, TblClf.ClfRso, TblInt.IntFat, TblArt.ArtDeb, TblIntArt.IntArtQta, TblArt_1.ArtDeb, TblIntArt.IntArtIni, TblIntArt.IntArtFin FROM TblDep INNER JOIN (TblClf INNER JOIN ((TblInt LEFT JOIN ((TblIntArt LEFT JOIN TblCol ON TblIntArt.ColKey = TblCol.ColKey) LEFT JOIN TblArt ON TblIntArt.ArtKey = TblArt.ArtKey) ON TblInt.IntKey = TblIntArt.IntKey) LEFT JOIN ((TblIntMac LEFT JOIN TblMac ON TblIntMac.MacKey = TblMac.MacKey) LEFT JOIN TblArt AS TblArt_1 ON TblMac.ArtKey = TblArt_1.ArtKey) ON TblIntArt.IntArtKey = TblIntMac.IntArtKey) ON TblClf.ClfKey = TblInt.ClfKey) ON TblDep.DepKey = TblInt.DepKey WHERE TblInt.IntDat=@IntDat ORDER BY TblInt.IntKey DESC", Connessione) 
      
      
      
      Dim dsInterventi As New System.Data.DataSet() 
      cmd.SelectCommand.Parameters.Add ("@IntDat", System.Data.SqlDbType.SmallDateTime) 



      cmd.SelectCommand.Parameters("@Intdat").Value = me.Calendar1.SelectedDate


      cmd.Fill(dsInterventi) 
         Cal_int_datagrid.Datasource = dsInterventi
      Cal_int_datagrid.Databind()
   End Sub
  </script>