function getAjaxData(url, callback){
    var xmlHttp;
    try{
        xmlHttp=new XMLHttpRequest();
    }
    catch (e){
        // Internet Explorer
        try {
            xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e){
            try{
                xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (e){
                //alert("Your browser does not support AJAX!");
                return false;
            }
        }
    }

    xmlHttp.open("GET",url,true);
    xmlHttp.onreadystatechange=function(){
        if(xmlHttp.readyState==4){
            callback(xmlHttp.responseText);
        }
    }
    xmlHttp.send(null);
}
function vote(id, v){
    getAjaxData("/ajax/vote.php?id="+id+"&vote="+v, function(res){
        var elm = document.getElementById('v'+id);
        if (elm){
            if (res == '1'){
                elm.innerHTML = 'voted';
                if (v == 1){
                    elm.style.backgroundColor = '#B1F598';
                } else {
                    elm.style.backgroundColor = '#FFA9A3';
                }
            } else if (res == '0'){
                elm.innerHTML = 'voted';
            } else {
                elm.innerHTML = 'error';
            }
        }
    });
}