How to import contacts from Gmail using ASP.NET

<html></html>
<body>
    <form id="form1">
        <div>
            <table>
                <tr>
                    <td>UserName</td>
                    <td>
                        <asp:TextBox ID="txtgmailusername" runat="server"></asp:TextBox>
                    </td>
                </tr>
                <tr>
                    <td>Password</td>
                    <td>
                        <asp:TextBox ID="txtpassword" runat="server"TextMode="Password"></asp:TextBox>
                    </td>
                </tr>
                <tr>
                    <td></td>
                    <td>
                        <asp:Button ID="Button1" runat="server" Text="Button"onclick="Button1_Click" />
                    </td>
                </tr>
            </table>
        </div>
        <div>
            <asp:GridView ID="gvmails" runat="server"></asp:GridView>
        </div>
    </form>
</body>

</html>

using Google.GData.Contacts;
using Google.GData.Client;
using Google.GData.Extensions;
using Google.Contacts;

Imports Google.GData.Contacts
Imports Google.GData.Client
Imports Google.GData.Extensions
Imports Google.Contacts
Imports System.Data

public static DataSet GetGmailContacts(string App_Name, string Uname, string UPassword)
{
    DataSet ds = new DataSet();
    DataTable dt = new DataTable();
    DataColumn C2 = new DataColumn();
    C2.DataType = Type.GetType("System.String");
    C2.ColumnName = "EmailID";
    dt.Columns.Add(C2);
    RequestSettings rs = new RequestSettings(App_Name, Uname, UPassword);
    rs.AutoPaging = true;
    ContactsRequest cr = new ContactsRequest(rs);
    Feed < Contact > f = cr.GetContacts();
    foreach(Contact t in f.Entries)
    {
        foreach(EMail email in t.Emails)
        {
            DataRow dr1 = dt.NewRow();
            dr1["EmailID"] = email.Address.ToString();
            dt.Rows.Add(dr1);
        }
    }
    ds.Tables.Add(dt);
    return ds;
}
Protected void Button1_Click(object sender, EventArgs e)
{
    DataSet ds = GetGmailContacts("MyNetwork Web Application!", txtgmailusername.Text, txtpassword.Text);
    gvmails.DataSource = ds;
    gvmails.DataBind();
}

Public Shared Function GetGmailContacts(App_Name AsString, Uname As String, UPassword As String) As DataSet
Dim ds As New DataSet()
Dim dt As New DataTable()
Dim C2 As New DataColumn()
C2.DataType = Type.[GetType]("System.String")
C2.ColumnName = "EmailID"
dt.Columns.Add(C2)
Dim rs As New RequestSettings(App_Name, Uname, UPassword)
rs.AutoPaging = True
Dim cr As New ContactsRequest(rs)
Dim f As Feed(Of Contact) = cr.GetContacts()
For Each t As Contact In f.Entries
For Each email As EMail In t.Emails
Dim dr1 As DataRow = dt.NewRow()
dr1("EmailID") = email.Address.ToString()
dt.Rows.Add(dr1)
Next
Next
ds.Tables.Add(dt)
Return ds
End Function
Protected Sub Button1_Click(sender As Object, e AsSystem.EventArgs) Handles Button1.Click
Dim ds As DataSet = GetGmailContacts("MyNetwork Web Application!", txtgmailusername.Text, txtpassword.Text)
gvmails.DataSource = ds
gvmails.DataBind()
End Sub