JSON parsing from cross domain using jquery ajax

Im trying to parse json from cross domain but im getting error like 405 (Method Not Allowed) in jquery plugin (im using latest plugin only from google) Any solution or suggestions will be great help for me.

Thanks Basha

Here is my code

$(document).ready(function() {
    $.ajax({
    type: "GET",
    url: "http://myurl.com/webservice&callback=?",          
    contentType: "application/json; charset=utf-8",
    crossDomain: true,
    dataType: "jsonp",
    data: "{}",
    Accept: "",
    beforeSend: setHeader,
    success: OnGetAllMembersSuccess,
    error: OnGetAllMembersError,                
    });
});     
function setHeader(req) {
    req.setRequestHeader("Authentication", "Basic credentials");
    req.setRequestHeader("Content-Type", "application/json");
    req.setRequestHeader("Accept", "application/json");
}    

function OnGetAllMembersSuccess(data, status) {
    alert(status);
    $.each(data.result, function(key, value) {              
        $("#result").append(key+" : "+value);
        $("#result").append("<br />");
    });
}

function OnGetAllMembersError(request, status, error) {
    alert(status);
}