Asyncrhonous Ajax request modifing the session

Do not call 2 controller methods modifying session with Ajax asynchronously.

I searched hours for this bug in my code....

if the Task controller methods "select_project" and "select_project_resp" modify the session, then this code will ends up in a race condition. The resulting session will contain only the last modification.

function select_project(str){
    if (str == "") return;
    Element.show('loading');
    new Ajax.Request('/task/select_project/' + str, {
        asynchronous: true,
        evalScripts: true,
        onComplete: function(request){
            display_tasks(request.responseText)
        }
    });
    new Ajax.Request('/task/show_project_resp/' + str, {
         asynchronous: true,
         evalScripts: true,
         onComplete: function(request){
             display_project_resp(request.responseText)
         }
    });
    return false;
}

Instead, call the second method after the first one finished:

function select_project(str){
    if (str == "") return;
    Element.show('loading');
    new Ajax.Request('/task/select_project/' + str, {
        asynchronous: true,
        evalScripts: true,
        onComplete: function(request){
            display_tasks(request.responseText)
            // to avoid race condition and mix the sessions,
            // the second Ajax request is not done asynchronously
            // but following the first....
            new Ajax.Request('/task/show_project_resp/' + str, {
                asynchronous: true,
                evalScripts: true,
                onComplete: function(request){
                    display_project_resp(request.responseText)
                }
            });
        }
    });
    return false;
}

See http://www.chipmunkninja.com/article/asyncsessions