Ajax Call - simple web service method returns entire page

Question

I have a simple function in my web service.

` [WebMethod]

public string TryWB()

{

string sMsg = "try";

return sMsg;

} `

and I am calling it from my aspx page..

at the top i have tried

[ScriptMethod( ResponseFormat= ResponseFormat.Json)]

(or .xml or even httpget)

and in the function also I have tried serialising it with

sMsg = (new JavaScriptSerializer()).Serialize(sMsg);

or even made custom object just to wrap message and even tried

JsonConvert.SerializeObject(cm,Newtonsoft.Json.Formatting.Indented);

From my aspx pages all combinations of text, xml, json made

$.ajax({

URL: 'FLMSWebService/Login.asmx/TryWB',

method:"POST", (get also tried)

contentType: "application/json; charset=utf-8",

dataType: "text",

success: function (data) {

alert('success');

alert(JSON.stringify(data));

},

error: function (jqXHR, exception) {

alert(jqXHR.responseText);

}});

contentType: json, xml tried

datatype : xml , json tried...

in web.config also

<system.webServer>

<modules>

<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>

</modules>

and

<system.web.extensions>

<scripting>

<webServices>

<authenticationService enabled="true" />

</webServices>

</scripting>

</system.web.extensions>

this is all i got from my 2 day search on net...but main point if i have

dataType: "text",

its a success and full page returned as data

in every other datatype or contenttype i get error

and the full page is shown in

alert(jqXHR.responseText);

in the error callback

I am stuck!! please help