function dobutt(button, state){
    var li=button.src.length-5;
    button.src = button.src.substring(0, li) + state+'.png';
}
function ShowAnswer(answer, qw)
{
    var isshow = (document.getElementById(answer).style.display == '')? false : true;
    var qwtext = qw.innerHTML.toString();
    qw.innerHTML = qwtext.replace((isshow)?"+":"-", (isshow)?"-":"+");
    document.getElementById(answer).style.display = (isshow) ? "" : "none";
    qw.className = (isshow)? "faq_item_open" : "faq_item_close";
}