How to get the data from datatable and put on a sqldasource ??

i got this error when i tried like you show above:

System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.InvalidOperationException: There was an error generating the XML document. ---> System.InvalidOperationException: Cannot serialize the DataTable. DataTable name is not set.
  at System.Data.DataTable.WriteXmlSchema(XmlWriter writer, Boolean writeHierarchy)
  at System.Data.DataTable.System.Xml.Serialization.IXmlSerializable.WriteXml(XmlWriter writer)
  at System.Xml.Serialization.XmlSerializationWriter.WriteSerializable(IXmlSerializable serializable, String name, String ns, Boolean isNullable, Boolean wrapped)
  at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationWriter1.Write57_Item(Object[] p)
  at Microsoft.Xml.Serialization.GeneratedAssembly.ArrayOfObjectSerializer113.Serialize(Object objectToSerialize, XmlSerializationWriter writer)
  at System.Xml.Serialization.XmlSerializer.Serialize(XmlWriter xmlWriter, Object o, XmlSerializerNamespaces namespaces, String encodingStyle, String id)
  --- End of inner exception stack trace ---
  at System.Xml.Serialization.XmlSerializer.Serialize(XmlWriter xmlWriter, Object o, XmlSerializerNamespaces namespaces, String encodingStyle, String id)
  at System.Web.Services.Protocols.SoapServerProtocol.WriteReturns(Object[] returnValues, Stream outputStream)
  at System.Web.Services.Protocols.WebServiceHandler.WriteReturns(Object[] returnValues)
  at System.Web.Services.Protocols.WebServiceHandler.Invoke()
  --- End of inner exception stack trace ---

component:

       <asp:DropDownList ID="DDLEscolaridade" runat="server" SkinID="ddlnormal" DataSourceID="ObjectDataSource1"  DataTextField="Escolaridade" DataValueField="ID">
       </asp:DropDownList>



the code page:

Imports System.Data.SqlClient
Imports System.Data.SqlDbType
Imports System.Data

Partial Class _Default
    Inherits SecurityPage
    Dim GlobalNucleo As New GlobalNucleo_WebService.GlobalNucleo_WebService

    Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        DDLEscolaridade.DataSource = GlobalNucleo.GlobalTable_Get_Escolaridade()
        DDLEscolaridade.DataBind()
    End Sub
End Class


Here is on the webservice:

    <WebMethod()> _
    Public Function GlobalTable_Get_Escolaridade() As DataTable
        Dim Table As New DataTable()
        Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("GlobalNucleoConnectionString").ConnectionString)
            Using command As New SqlCommand("SP_Global_Get_Escolaridade", connection)
                command.CommandType = CommandType.StoredProcedure
                connection.Open()
                Dim adapt As New SqlDataAdapter(command)
                adapt.Fill(Table)
            End Using
        End Using
        Return Table
    End Function


here is the storeprocedure:

use [databasename]
GO
/****** Object:  StoredProcedure [dbo].[SP_Global_Get_Escolaridade]    Script Date: 09/14/2010 11:38:24 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[SP_Global_Get_Escolaridade]
AS
         SELECT * from TB_GLOBAL_ESCOLARIDADE
RETURN


here is the table structure:

id   escolaridade
1    highschool
2    lskjdf lsdjfls
3   sldjflskjdfljsldf

btw, i add the webservice to the App_WebReferences

found the solution:

here is how:

added this line to the webservice function:

                Table.TableName = "Escolaridade"

Thanks guys,