asp.net 2.0 jquery if exists

$(document).ready(function () { 
var JSONObject = new Object; //Initialize a new JSON object as this is the most common mistake making a JSON object 

$('#btn').click( 
function () { 

JSONObject.name = $('#lid').val().toString(); //Read Data from a textbox with id = lid 
JSONstring = JSON.stringify(JSONObject); //Stringyfy in JSON format 
alert(JSONstring); //Alert to check your request you can remove later on   /// Error it stops here does not post. but returns name
$( ".result" ).html( JSONstring )
$.ajax({ 
type: "POST", 
url: "test.aspx/checkExists", // Request Post to page Test1.aspx and calling method GreetingMessage 
data: JSONstring, // Pass Request String 
contentType: "application/json; charset=utf-8", 
dataType: "json", 
success: function (response) { 
//alert(response.d.toString() + " good"); 
$( ".result" ).html( response.d.toString() );
}, 
error: function (xhr, ajaxOptions, thrownError) { 
alert(xhr.status); 
alert(thrownError); 
$( ".result" ).html( response.d.toString() );
} 
}); 
} 
); 

}); //close ready

 public static string checkExists(string name) //Method should be declared as static 
        {
            return "your name exists " + name + Environment.NewLine + "this is your name";
        }