从另一个组合框选择组合框填充？

Question

  Protected Sub rcmbDatabaselist_SelectedIndexChanged(sender As Object, e As Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs) Handles rcmbDatabaselist.SelectedIndexChanged
                Try
                    Dim strDestinationConnString As String = "Data Source=.;Initial Catalog=" & rcmbDatabaselist.SelectedValue & ";Persist Security Info=True;User ID=sa;Password=ssmits"
                    ViewState("strSyncDestinationConnString") = strDestinationConnString

                    Call getDestinationTableList()
                Catch ex As Exception

                End Try
            End Sub
            Protected Sub rcmbTableList_SelectedIndexChanged(sender As Object, e As Telerik.Web.UI.RadComboBoxSelectedIndexChangedEventArgs) Handles rcmbTableList.SelectedIndexChanged
                Try
                    Call getDestinationClmList(rcmbTableList.SelectedValue)
                Catch ex As Exception

                End Try
            End Sub

2以上是事件 以下代码是如何填写网页的功能。

自动回发是真的。 我调试时没有给出错误。