HelloWorldWebService.cs 

  [WebService (Namespace = "http://tempuri.org/")] 
  [WebServiceBinding (ConformsTo = WsiProfiles.BasicProfile1_1)] 
  [System.Web.Script.Services.ScriptService ()]// must write 
  Public class HelloWorldWebService: System.Web.Services.WebService ( 

  Public HelloWorldWebService () ( 

  / / If the use of design components, please note the following line 
  / / InitializeComponent (); 
  ) 

[WebMethod]
  Public string HelloWorld (string name) ( 
  Return "Welcome to website" + name; 
  ) 

  ) 

  HelloWorld.aspx 

  <script Type="text/javascript"> 
  Var g_tbName = null; 
  Var g_btnSayHello = null; 
  Var g_lbMsg = null; 

  Function pageLoad () ( 
  G_tbName = new Sys.Preview.UI.TextBox ($ get ( 'tbName')); 
  G_tbName.initialize (); 
  G_btnSayHello = new Sys.Preview.UI.Button ($ get ( 'btnSay')); 
  G_btnSayHello.add_click (getServerHello); 
  G_btnSayHello.initialize (); 
  G_lbMsg = new Sys.Preview.UI.Label ($ get ( 'lblMsg')); 
  G_lbMsg.initialize (); 
  ) 
  Function getServerHello () ( 
  HelloWorldWebService.HelloWorld (g_tbName.get_text (), cb_getServerHello); 
  ) 
  Function cb_getServerHello (result) ( 
  G_lbMsg.set_text (result); 
  ) 
  </ Script> 

  <form Id="form1" runat="server"> 
  <asp:ScriptManager ID="ScriptManager1" runat="server"> 
<Scripts>
  <asp:ScriptReference Name="PreviewScript.js" Assembly="Microsoft.Web.Preview" /> 
  </ Scripts> 
<Services>
  <asp:ServiceReference Path="HelloWorldWebService.asmx" /> 
  </ Services> 
  </ Asp: ScriptManager> 
<div>
  <asp:TextBox ID="tbName" runat="server"> </ asp: TextBox> 
  <input ID="btnSay" type="button" value="Button" /> 
  <br /> 
  <asp:Label ID="lblMsg" runat="server"> </ asp: Label> </ div> 
  </ Div ><!-- form, do not necessarily have to server controls, html can, as long as the correct id attribute on the trip ->