C# - Call Method In Code Behind From JQuery

I am trying to execute a method in ASP.NET from Jquery

$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "MyMessages.aspx?id=66&epslanguage=sv/test",
data: "{}",
dataType: "json",
error: function(xhr, err) {
alert("readyState: " + xhr.readyState + "
status: " + xhr.status);
alert("responseText: " + xhr.responseText);
},
success: function() {
alert("it works" );
}
})

code behind:

[WebMethod]
protected void test()
{
test.Text = "works";
}

I get errormessage redayState: 4 and status 200 when I do this. I don't understand the problem. I am vey new at this. :)