Page Methods Jquery ...

Here we will use jQuery to call an ASP.NET AJAX page method.That shows you how to use jQuery almost exactly as you wanted.?Here is the example:

Consider the following page method:

[WebMethod]
public static bool IsUniqueEmailAddress(string emailAddress)
{
    // do some processing here
    return true;
}

To call this page method you must add an ASP.NET ScriptManager control, but with using a jQuery function you can simply add a reference to jQuery to your page an use a method call much like this:

function emailBlur(ctl)
{
    CallPageMethod("IsUniqueEmailAddress", onSuccess, onFail, "emailAddress", ctl.value);
}


To get this all to work consider that the emailBlur function is wired up to the onblur client event handler of an input text box. Then when calling the CallPageMethod function you pass in the name of the page method as a string and references to the "success" and "failure" functions.

CallPageMethod Code:

To get it all to work you need a reference to jQuery on your page and the following code:

function CallPageMethod(methodName, onSuccess, onFail) {
    var args = ;
    var l = arguments.length;
    if (l > 3) {
        for (var i = 3; i < l - 1; i += 2) {
            if (args.length != 0) args += ,;
            args += " + arguments[i] + ":" + arguments[i + 1] + ";
        }
    }
    var loc = window.location.href;
    loc = (loc.substr(loc.length - 1, 1) == "/") ? loc + "default.aspx" : loc;
    $.ajax({
        type: "POST",
        url: loc + "/" + methodName,
        data: "{" + args + "}",
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: onSuccess,
        fail: onFail
    });
}

 Original Source:
http://weblogs.asp.net/craigshoemaker/archive/2008/09/29/using-jquery-to-call-asp-net-ajax-page-methods.aspx