Import Gmail Contacts in Asp.Net

First of all download Google Data API and install to get following dlls
1. Google.GData.Client
2. Google.GData.Contacts
3. Google.GData.Extensions
Put these 3 dlls in BIN folder of application also add reference to your project for them.
using Google.Contacts;
using Google.GData.Client;
using Google.GData.Contacts;
using Google.GData.Extensions;<b>Email: </b>
<asp:TextBox ID="txtEmail" runat="server"> </asp:TextBox>
<b>Password : </b>
<asp:TextBox ID="txtPassword" runat="server" TabIndex="1" TextMode="Password">
</asp:TextBox>
<asp:Button ID="btnContacts" runat="server"  onclick="btnContacts_Click"
TabIndex="2" Text="Import Contacts"  Width="125px" />
<asp:ListBox ID="lstContacts" runat="server" Height="176px" Width="229px">
 </asp:ListBox>
protected void btnContacts_Click(object sender, EventArgs e)
    {
        //Provide Login Information
        RequestSettings rsLoginInfo = new RequestSettings("", txtEmail.Text, txtPassword.Text);
        rsLoginInfo.AutoPaging = true;
        // Fetch contacts and dislay them in ListBox
        ContactsRequest cRequest = new ContactsRequest(rsLoginInfo);
        Feed <contact> feedContacts = cRequest.GetContacts();
        foreach (Contact gmailAddresses in feedContacts.Entries)
        {
            Console.WriteLine("\t" + gmailAddresses.Title);
            lstContacts.Items.Add(gmailAddresses.Title);
            foreach (EMail emailId in gmailAddresses.Emails)
            {
                Console.WriteLine("\t" + emailId.Address);
                lstContacts.Items.Add(" " + emailId.Address);
            }
        }
    }