<div>
    <input type="text" id="name" />
    <input type="button" id="send" value="Send" />
</div>

public partial class Page : Canvas
{
    public void Page_Loaded(object o, EventArgs e)
    {
        // Required to initialize variables
        InitializeComponent();
    }
}

public partial class Page : Canvas
{
    public void Page_Loaded(object o, EventArgs e)
    {
        // Required to initialize variables
        InitializeComponent();

        // Get the HTML Document
        HtmlDocument document = HtmlPage.Document;

        // Get the 2 HTML elements by their ID
        HtmlElement textbox = document.GetElementByID("name");
        HtmlElement button = document.GetElementByID("send");

        if (textbox != null)
        {
            // we set the value attribute to DVP
            textbox.SetAttribute("value", "DVP");
        }
        if (button != null)
        {
            // we add an event to the button
            // when the button will be clicked the event onJump will be called
            button.AttachEvent("onclick", new EventHandler<HtmlEventArgs>(this.OnJump));
        }
    }

    private void OnJump(object sender, EventArgs e)
    {
        // we send the user to this URI
        HtmlPage.Navigate("http://broux.developpez.com");
    }
}

[WebMethod]
[System.Web.Script.Services.ScriptMethod(UseHttpGet=true)]
public string HelloWorld(string input)
{
    if (input == null) input = "Anonym";
    return "Hello World " + input;
}

<webServices>
    <protocols>
        <add name="HttpGet"/>
        <add name="HttpPost"/>
    </protocols>
</webServices>

<?xml version="1.0" encoding="utf-8" ?> 
<string xmlns="http://tempuri.org/">Hello World Sky</string> 

<TextBlock x:Name="helloWorld" Name="helloWorld"></TextBlock>

public partial class Page : Canvas
{
    public void Page_Loaded(object o, EventArgs e)
    {
        // Required to initialize variables
        InitializeComponent();
    }
}

public partial class Page : Canvas
{
    // an BrowserHttpRequest for execute our HTTP Request
    private BrowserHttpWebRequest mRequest;

    public void Page_Loaded(object o, EventArgs e)
    {
        // Required to initialize variables
        InitializeComponent();

        try
        {
            // replace the port by yours
            mRequest = new BrowserHttpWebRequest(new Uri("http://localhost:50436/Service1.asmx/HelloWorld?input=Sky"));

            // Get the response to the request
            // You can call it asynchronously too
            HttpWebResponse response = (HttpWebResponse)mRequest.GetResponse();

            // Read response
            StreamReader responseReader = new StreamReader(response.GetResponseStream());
            // Read all the responde (ie : the XML text returned)
            string allResponse = responseReader.ReadToEnd();
            // We create en XML Reader with the XML text returned
            XmlReader xr = XmlReader.Create(new StringReader(allResponse));
            // Method return string so we search the string markup
            xr.ReadToFollowing("string");
            // Get following text node
            xr.Read();

            // we display the result in the TextBlock
            helloWorld.Text = xr.Value;

            // Close th XmlReader and the HTTP Request
            xr.Close();
            mRequest.Close();
        }
        catch (Exception ex)
        {
            // if error, we display the exception's message in the textblock
            helloWorld.Text = ex.Message;
        }
    }
}

// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
//[System.Web.Script.Services.ScriptService]

// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
[System.Web.Script.Services.ScriptService]

<TextBlock x:Name="helloWorld" Name="helloWorld"></TextBlock>

public partial class Page : Canvas
{
    public void Page_Loaded(object o, EventArgs e)
    {
        // Required to initialize variables
        InitializeComponent();
    }
}

public partial class Page : Canvas
{
    Service1.Service1 mService;

    public void Page_Loaded(object o, EventArgs e)
    {
        // Required to initialize variables
        InitializeComponent();

        // we instanciate our proxy
        mService = new Service1.Service1();

        // we call our method asynchronously
        // when the result will be available the event OnIHaveMyResponse will be called
        IAsyncResult iar = mService.BeginHelloWorld(new AsyncCallback(OnIHaveMyResponse), mService);
    }

    public void OnIHaveMyResponse(IAsyncResult iar)
    {
        // the method is finish we get our result (which is a string)
        string res = ((Service1.Service1)iar.AsyncState).EndHelloWorld(iar);

        // we display it on our TextBlock
        helloWorld.Text = res;
    }
}