Hi experts. i got this asp.net that supposed to add records to matches table. but when i fill the text boxes
i get the following error.I be happy if some one help me fix this broken code.Thanks

Code:
ERROR: Could not add record, please ensure the fields are correctly filled out
Code:
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<html>
<script language="VB" runat="server">

    Dim MyConnection As SqlConnection

    Sub Page_Load(Sender As Object, E As EventArgs) 

        MyConnection = New SqlConnection("server=(local);database=teniss2;User Id=web;Password=web;")

        If Not (IsPostBack)
            BindGrid()
        End If
    End Sub

    Sub Addmatches_Click(Sender As Object, E As EventArgs) 

        Dim DS As DataSet
        Dim MyCommand As SqlCommand

        If MATCHNO.Value = "" Or TEAMNO.Value = "" Or PLAYERNO.Value = "" Or WON.Value = ""

          Message.InnerHtml = "ERROR: Null values not allowed "
          Message.Style("color") = "red"
          BindGrid()
        End If

        Dim InsertCmd As String = "insert into matches (MATCHNO, TEAMNO, PLAYERNO ,WON, LOST) values (@LMATCHNO, @LTEAMNO, @LPLAYERNO, @LWON, @LLOST;)"

        MyCommand = New SqlCommand(InsertCmd, MyConnection)

        MyCommand.Parameters.Add(New SqlParameter("@LMATCHNO", SqlDbType.NVarChar, 11))
        MyCommand.Parameters("@LMATCHNO").Value = Server.HtmlEncode(MATCHNO.Value)

        MyCommand.Parameters.Add(New SqlParameter("@LTEAMNO", SqlDbType.NVarChar, 40))
        MyCommand.Parameters("@LTEAMNO").Value = Server.HtmlEncode(TEAMNO.Value)

        MyCommand.Parameters.Add(New SqlParameter("@LPLAYERNO", SqlDbType.NVarChar, 20))
        MyCommand.Parameters("@LPLAYERNO").Value = Server.HtmlEncode(PLAYERNO.Value)

        MyCommand.Parameters.Add(New SqlParameter("@LWON", SqlDbType.NChar, 12))
        MyCommand.Parameters("@LWON").Value = Server.HtmlEncode(WON.Value)

        MyCommand.Parameters.Add(New SqlParameter("@LLOST", SqlDbType.NVarChar, 40))
        MyCommand.Parameters("@LLOST").Value = Server.HtmlEncode(LOST.Value)

     

        MyCommand.Connection.Open()

        Try 
            MyCommand.ExecuteNonQuery()
            Message.InnerHtml = "<b>Record Added</b><br>" & InsertCmd.ToString()

        Catch Exp As SQLException
            If Exp.Number = 2627
                Message.InnerHtml = "ERROR: A record already exists with the same primary key"
            Else
                Message.InnerHtml = "ERROR: Could not add record, please ensure the fields are correctly filled out"
            End If
            Message.Style("color") = "red"

        End Try

        MyCommand.Connection.Close()

        BindGrid()
    End Sub

    Sub BindGrid() 

        Dim MyCommand As SqlDataAdapter = new SqlDataAdapter("select * from matches", MyConnection)

        Dim DS As DataSet = new DataSet()
        MyCommand.Fill(DS, "matches")

        MyDataGrid.DataSource=DS.Tables("matches").DefaultView
        MyDataGrid.DataBind()
    End Sub

</script>

<body style="font: 10pt verdana">

  <form runat="server">

    <h3><font face="Verdana">Inserting A MATCHES RECORD</font></h3>

    <table width="95%">
      <tr>
        <td valign="top">

          <ASP:DataGrid id="MyDataGrid" runat="server"
            Width="700"
            BackColor="#ccccff" 
            BorderColor="black"
            ShowFooter="false" 
            CellPadding=3 
            CellSpacing="0"
            Font-Name="Verdana"
            Font-Size="8pt"
            HeaderStyle-BackColor="#aaaadd"
            EnableViewState="false"
          />

        </td>
        <td valign="top">

          <table style="font: 8pt verdana">
            <tr>
              <td colspan="2" bgcolor="#aaaadd" style="font:10pt verdana">Add a New record:</td>
            </tr>
            <tr>
              <td nowrap>MATCHNO: </td>
              <td><input type="text" id="MATCHNO" value="0000" runat="server"></td>
            </tr>
            <tr>
              <td nowrap>TEAMNO: </td>
              <td><input type="text" id="TEAMNO" value="0000" runat="server"></td>
            </tr>  
            <tr nowrap>
              <td>Playerno: </td>
              <td><input type="text" id="PLAYERNO" value="0000" runat="server"></td>
            </tr>
            <tr>
              <td>Won: </td>
              <td><input type="text" id="WON" value="0000" runat="server"></td>
            </tr>
            <tr>
              <td>Lost: </td>
              <td><input type="text" id="LOST" value="0000" runat="server"></td>
            </tr>
           
              <td></td>
              <td style="padding-top:15">
                <input type="submit" OnServerClick="Addmatches_Click" value="Add matches" runat="server">
              </td>
            </tr>
            <tr>
              <td colspan="2" style="padding-top:15" align="center">
                <span id="Message" EnableViewState="false" style="font: arial 11pt;" runat="server"/>
              </td>
            </tr>
          </table>

        </td>
      </tr>
    </table>

  </form>

</body>
</html>