function showdateVoid()
{
    var span=document.getElementById("showdate");
    if(span){
        var d = new Date()
        var vYear = d.getFullYear()
        var vMon = d.getMonth() + 1
        var vDay = d.getDate()
        var html=vYear;
        html+="年";
        html+=vMon<10 ? "0" + vMon : vMon;
        html+="月";
        html+=vDay<10 ?  "0"+ vDay : vDay;
        html+="日";
        html+=" 星期";
        var xq=d.getDay();
        if(xq==1){
            html+="一";
        }
        if(xq==2){
            html+="二";
        }
        if(xq==3){
            html+="三";
        }
        if(xq==4){
            html+="四";
        }
        if(xq==5){
            html+="五";
        }
        if(xq==6){
            html+="六";
        }
        if(xq==0){
            html+="日";
        }
        span.innerHTML=html;        
    }
    else{
        alert("no span");
    }
}
showdateVoid();