Chat Dark Code

__dark = false;

__t = document.createElement("input");
__t.type = "button";
__t.value = "Dark";
tag("#chatbox_header").appendChild(__t);

__s = document.createElement("style");
__s.innerHTML = ".chatDark { background-color: #333!important; }"+
                ".chatDark * { background-color: #333!important; color: #CCC!important;}";
tag("#chatbox_header").appendChild(__s);

__t.onclick = function(){
    if(__dark){
        tag("#chatbox_members").setAttribute("class", "chatbox-members");
        tag("#chatbox").setAttribute("class", "teste");
        __dark = false;
    } else {
        tag("#chatbox_members").setAttribute("class", "chatDark");
        tag("#chatbox").setAttribute("class", "chatDark");
        __dark = true;
    }
};

function tag(t){
    var r;
    if(t.substr(0, 1) == "@"){
        r = document.getElementsByName( t.substring(1, t.length) );
    }
    else{
        r = document.querySelectorAll(t);
    }
    var teste = t.split(" ");
    teste = teste[teste.length-1].indexOf("#");
    if(teste != -1){
        return r[0];
    }else{ return r; }

}