var output = $("#output");
    var scripts = "";

    for(var i = 0; i < js_editors.length; i++){
            scripts += js_editors[i].getValue();
    }

    output.html(scripts);
    eval(output.html());

var gamefield;

var onStartFunction;
var onEndFunction;

/** set a function to be executed when the game just startet */
this.onSta