title: My textbox is not filled with data
body: <pre><code>Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
      If Not IsPostBack Then
          TextBox3.Text = Now()
          Dim com As New SqlCommand
          com.CommandType = CommandType.Text
          com.CommandText = "select  productname ,productid,productdescreption,price from products order by productname "
          com.Connection = con
          Dim ad As New SqlDataAdapter
  
          Dim ds As New DataSet
          ad.SelectCommand = com
          ad.Fill(ds)
  
          DropDownList1.DataSource = ds
          DropDownList1.DataTextField = "productname"
  
          DropDownList1.DataValueField = "productid"
          'Dim ss As Integer
          'ss = Convert.ToInt32(DropDownList1.DataValueField)
          'DropDownList1.DataValueField = ss
  
          DropDownList1.DataBind()
  
  
          Dim com2 As New SqlCommand
          com2.CommandType = CommandType.Text
          com2.CommandText = "select  dealername ,dealerid from dealerin order by dealername  "
          com2.Connection = con
          Dim ad2 As New SqlDataAdapter
  
          Dim ds2 As New DataSet
          ad2.SelectCommand = com2
          ad2.Fill(ds2)
  
          DropDownList2.DataSource = ds2
          DropDownList2.DataTextField = "dealername"
          DropDownList2.DataValueField = "dealerid"
          DropDownList2.DataBind()
  
  
  
          'Dim com3 As New SqlCommand
          'com3.CommandType = CommandType.Text
          'com3.CommandText = "select distinct productname ,productid,productdescreption from products "
          'com3.Connection = con
          'Dim ad3 As New SqlDataAdapter
  
          'Dim ds3 As New DataSet
          'ad2.SelectCommand = com3
          'ad2.Fill(ds3)
  
          'DropDownList3.DataSource = ds3
          'DropDownList3.DataTextField = "productdescreption"
          'DropDownList3.DataValueField = "productid"
          'DropDownList3.DataBind()
  
      End If
  
  
  End Sub
  Dim dss As New DataSet
  Public Function getproduct_byid(ByVal productid As Integer) As DataSet
      Try
          Dim com3 As New SqlCommand
          com3.CommandType = CommandType.StoredProcedure
          com3.CommandText = "getproduct_byid"
          com3.Connection = con
          'com.Parameters.AddWithValue("@productid", productid)
          Dim adapter3 As New SqlDataAdapter(com3)
  
          adapter3.Fill(dss, "product")
          Return dss
      Catch ex As Exception
          Response.Write("error due to " &amp; ex.Message)
      End Try
  
  End Function
  
  Protected Sub DropDownList1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles DropDownList1.SelectedIndexChanged
      Try
  
          getproduct_byid(DropDownList1.SelectedValue)
          If dss.Tables("product").Rows.Count = 1 Then
  
              TextBox5.Text = dss.Tables("product").Rows(0).Item("price")
  
  
          End If
      Catch ex As Exception
          Response.Write("error due to " &amp; ex.Message)
      End Try
  End Sub
  
  Protected Sub TextBox5_TextChanged(sender As Object, e As EventArgs) Handles TextBox5.TextChanged
      Try
          Dim a As Double
          Dim b As Double
          a = TextBox4.Text
          b = TextBox5.Text
          TextBox6.Text = A * b
      Catch ex As Exception
          Response.Write("error due to " &amp; ex.Message)
      End Try
  
  End Sub
  </code></pre>