Private Sub Form1_Load(sender As Object, e As EventArgs) Handles
    MyBase.Load
        Dim con As New SqlConnection
        con.ConnectionString = "data source=abc;initial
        catalog=LoginDB;integrated security=true"
        cmd.Connection = con
        con.Open()
        cmd.CommandText = "search_data"
        cmd.CommandType = CommandType.StoredProcedure
        Dim dset As New DataSet
        Dim dpt As New SqlDataAdapter
        dpt.SelectCommand = cmd
        dpt.Fill(dset, "tab")
        ComboBox1.DataSource = dset.Tables("tab")
        ComboBox1.DisplayMember = "ID"
        ComboBox1.SelectedIndex = -1
    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As
    EventArgs) Handles ComboBox1.SelectedIndexChanged
        cmd.CommandText = "show_date"
        cmd.CommandType = CommandType.StoredProcedure

        p = New SqlParameter
        p.ParameterName = "@id"
        p.Value = ComboBox1.Text
        cmd.Parameters.Add(p)

        Dim dset As New DataSet
        Dim dpt As New SqlDataAdapter
        dpt.SelectCommand = cmd
        dpt.Fill(dset, "tab")
        If dset.Tables("tab").Rows.Count > 0 Then
        TextBox2.Text = dset.Tables("tab").Rows(0)("name")
        End If
    End Sub