使用document.getElementById获取d1，d2，d3，d4.
您使用了4个功能，但全部退出相同.这也是不好的做法.
试试这样的事情

Use document.getElementById for get d1,d2,d3,d4.
You used 4 functions but all are quit same. It is also bad practice.
Try some thing like this

function show1(id)
    {
    if(document.getElementById(id).style.display!=''block'')
    {
    document.getElementById("d1").style.display=''none'';
    document.getElementById("d2").style.display=''none'';
    document.getElementById("d3").style.display=''none'';
    document.getElementById("d4").style.display=''none'';    
    document.getElementById(id).style.display=''block'';
    }
    else
    {
    document.getElementById(id).style.display=''none'';
    }
    }

我有一个示例，请尝试理解它并在您的代码中使用它
这仅用于验证数字，即在您按下键时仅接收数字

Hi,
I have a example pls try to understand it and use it in your code
this is for validating only numbers ie it takes only numbers when you press the keys

function browsercompatbility() {

    if (browserName == "Netscape") {
        document.onkeydown = keyDown;
        document.captureEvents(Event.KEYDOWN);
        eventkey = keycode;
    }
    else {
        key = parseInt(event.keyCode);
        eventkey = key;
    }
}

function validatenumbers() {

    browsercompatbility();
    if ((parseInt(eventkey) >= 47) && (parseInt(eventkey) <= 57)) {
        return true;
    }
    else { eventkey = 0; return false; }
    return true;
}