function getStringShortDate(dateNumber)
{
    var d=new Date();
    d.setTime(dateNumber);
    document.write(d.getYear()+"-"+(d.getMonth()+1)+"-"+d.getDate());
    
}
function getStringLongDate(dateNumber)
{
    var date=new Date();
    date.setTime(dateNumber);
    document.write(date.toLocaleString());
    
}

function showDate()
{
    var d = new Date();  
    document.write(d.getYear()+"年"+(d.getMonth()+1)+"月"+d.getDate()+"日");
    switch(d.getDay())
    {
        case 0:
        document.write("  星期日");
        break;
        case 1:
        document.write("  星期一");
        break;
        case 2:
        document.write("  星期二");
        break;
        case 3:
        document.write("  星期三");
        break;
        case 4:
        document.write("  星期四");
        break;
        case 5:
        document.write("  星期五");
        break;
        case 6:
        document.write("  星期六");
        break;
    }
}

function getSubString(str,length)
{
    if(str.length<length)
        document.write(str);
    else{
        document.write(str.substring(0,length));
    }    
}