function checkOS(){
    var OSName="win";
    if (navigator.appVersion.indexOf("Win")!=-1) OSName="win";
    if (navigator.appVersion.indexOf("Mac")!=-1) OSName="mac";
    if (navigator.appVersion.indexOf("Linux")!=-1 || navigator.userAgent.indexOf("Linux")!=-1 || navigator.userAgent.indexOf("Unix")!=-1) OSName="win";
    return OSName;
}



function searchSymbol() {
    var os = checkOS();
    var symbol = document.getElementsByTagName('span');
    for (var i = 0; i < symbol.length; i++) {
        if (symbol[i].title) {
            if (symbol[i].title != os  && symbol[i].className == "key") {
                symbol[i].style.display = 'none';
            }
            //alert('ss');
        }
    }
}