有趣的待解难题：一个按钮同时能完成两个动作吗？

    下面是本人从网上找来的一段编号代码，此代码经几位网友的改进，现在很完善了，不过，我还想进一步改进，以便让自己与更多的初学者思考与学习。现在想改进的思路是：给此代码中的按钮“加”除了原友的加数功能外，还增加一个打印与否（带“打印”、“取消打印”两个按钮）的弹出窗体功能。但要注意，要打印的不是带编号的这个页面，而是另一个指定的页面。
     一般来说，要给这个按钮增加新的功能，需改此代码中的script部分，也就是代码中着红色的部分：window.onload = function(){
document.getElementById('add').onclick = function(){
changeNum(1);} 。不过，加入弹出窗体代码后要么编号增加功能失效，要么弹出窗体功能不全。可能是一个按钮无法同时完成两种动作造成。本人只是莱鸟，提不出更高明的方案，只得求高手帮助。<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<style type="text/css">
body{
margin-top: 0px;
}
#counter{
color:#F00;
font-size:36px;
}
</style>
</HEAD>
<TD   ALIGN="right"><FONT style="FONT-SIZE: 28pt; FONT-FAMILY: 宋体,"><font color="red"><script type="text/javascript">
var caution = false;
function setCookie(name, value, expires, path, domain, secure) {
var curCookie = name + "=" + escape(value) +
((expires) ? "; expires=" + expires.toGMTString() : "") +
((path) ? "; path=" + path : "") +
((domain) ? "; domain=" + domain : "") +
((secure) ? "; secure" : "") ;
if (!caution || (name + "=" + escape(value)).length <= 4000)
document.cookie = curCookie
else
if (confirm("Cookie exceeds 4KB and will be cut!"))
document.cookie = curCookie
}
function getCookie(name) {
var prefix = name + "="
var cookieStartIndex = document.cookie.indexOf(prefix)
if (cookieStartIndex == -1)
return null
var cookieEndIndex = document.cookie.indexOf(";", cookieStartIndex + prefix.length)
if (cookieEndIndex == -1)
cookieEndIndex = document.cookie.length
return unescape(document.cookie.substring(cookieStartIndex + prefix.length, cookieEndIndex))
}
function deleteCookie(name, path, domain) {
if (getCookie(name)) {
document.cookie = name + "=" +
((path) ? "; path=" + path : "") +
((domain) ? "; domain=" + domain : "") +
"; expires=Thu, 01-Jan-70 00:00:01 GMT"
}
}
function fixDate(date) {
var base = new Date(0)
var skew = base.getTime()
if (skew > 0)
date.setTime(date.getTime() - skew)
}
var now = new Date();
fixDate(now);
now.setTime(now.getTime() + 365 * 24 * 60 * 60 * 1000);
var totalLen = 6;
function changeNum(num){
var visits = getCookie("counter");
var str = ' ';
if (!visits || visits<=0){
visits = 1;
}else
{
visits =parseInt(visits)+num;
}
for(var i=0,len=visits.toString().length;i<totalLen-len;i++){
str += '0';     }
setCookie("counter", visits, now);
document.getElementById('counter').innerHTML = str+visits;
}     window.onload = function(){
document.getElementById('add').onclick = function(){
changeNum(1);
}
document.getElementById('reduce').onclick = function(){
changeNum(-1);
}
changeNum(0);
}
</script>
</font></font></TD>
<body>
<table >
<tbody>
<tr>
<td><input type="button" id="add" value="加"> <input type="button" id="reduce" value="减">
</td>
<td>
<div id="counter"></div>
</td></tr>
</tbody>
</table>
</body>
</html>

解决方案 »

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弹出窗体，只不过是一个带两个按钮的窗体，打印与取消打印，设置打开并打印指定网页即可（如**.html）。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>计数器</title>
<style type="text/css">
body{
    margin-top: 0px;
}
#counter{
    color:#F00;
    font-size:36px;
}
.info{
    height:70px;
    widht:100%;
    text-align:center;
    margin-top:30px;
}
.buttons{
    text-align:center;
}
</style>
</head>
<body>
<script type="text/javascript">
var caution = false;
function setCookie(name, value, expires, path, domain, secure) {
    var curCookie = name + "=" + escape(value) +
    ((expires) ? "; expires=" + expires.toGMTString() : "") +
    ((path) ? "; path=" + path : "") +
    ((domain) ? "; domain=" + domain : "") +
    ((secure) ? "; secure" : "") ;
    if (!caution || (name + "=" + escape(value)).length <= 4000)
        document.cookie = curCookie
    else
        if (confirm("Cookie exceeds 4KB and will be cut!"))
        document.cookie = curCookie
}
function getCookie(name) {
    var prefix = name + "="
    var cookieStartIndex = document.cookie.indexOf(prefix)
    if (cookieStartIndex == -1)
    return null
    var cookieEndIndex = document.cookie.indexOf(";", cookieStartIndex + prefix.length)
    if (cookieEndIndex == -1)
        cookieEndIndex = document.cookie.length
        return unescape(document.cookie.substring(cookieStartIndex + prefix.length, cookieEndIndex))
}
function deleteCookie(name, path, domain) {
    if (getCookie(name)) {
        document.cookie = name + "=" +
         ((path) ? "; path=" + path : "") +
        ((domain) ? "; domain=" + domain : "") +
         "; expires=Thu, 01-Jan-70 00:00:01 GMT"
    }
}
function fixDate(date) {
    var base = new Date(0)
    var skew = base.getTime()
    if (skew > 0)
        date.setTime(date.getTime() - skew)
}
var now = new Date();
fixDate(now);
now.setTime(now.getTime() + 365 * 24 * 60 * 60 * 1000);
var totalLen = 6;
function changeNum(num){
    var visits = getCookie("counter");
    var str = ' ';
    if (!visits || visits<=0){
        visits = 1;
    }else{
        visits =parseInt(visits)+num;
    }
    for(var i=0,len=visits.toString().length;i<totalLen-len;i++){
        str += '0';
    }
    setCookie("counter", visits, now);
    document.getElementById('counter').innerHTML = str+visits;
}     function cereateDiv(){
    var url = '';
    var div = document.createElement('div');
    var cw = Math.max(document.body.clientWidth , document.documentElement.clientWidth);
    var ch = Math.max(document.body.clientHeight , document.documentElement.clientHeight);
    div.style.position = 'absolute';
    div.style.width = '300px';
    div.style.height = '200px';
    div.style.border = '1px solid #000';
    div.style.top = ch/2 - 100+'px';
    div.style.left = cw/2 - 150+'px';
    div.style.zIndex = 99;
    document.body.appendChild(div);
    var cover = div.cloneNode();
    cover.style.width = cw + 'px';
    cover.style.height = ch + 'px';
    cover.style.border = 'none';
    cover.style.background = '#ddd';
    cover.style.top = '0px';
    cover.style.left = '0px';
    cover.style.position = 'absolute';
    cover.style.zIndex = 98;
    document.body.appendChild(cover);
    cover.style.opacity = 0.8
    cover.style.filter = 'alpha:(opacity=80)';
    div.innerHTML = '<div class="info">确定打印？</div><div class="buttons"><input type="button" id="confirm"  value="打印"/><input type="button" id="cancel" value="取消打印"/></div>'
    document.getElementById('confirm').onclick = function(){
        var target = window.open(url);
        target.print();//这里不知道能不能打印成功，如果新打开的页面是自己可以控制的话，建议打印代码放在这个页面里
        document.body.removeChild(cover);
        document.body.removeChild(div);
    }
    document.getElementById('cancel').onclick = function(){
        document.body.removeChild(cover);
        document.body.removeChild(div);
    }
}
window.onload = function(){
    document.getElementById('add').onclick = function(){
        changeNum(1);
        cereateDiv();
    }
    document.getElementById('reduce').onclick = function(){
        changeNum(-1);
    }
    changeNum(0);
}
</script>
<body>
    <table >
        <tbody>
            <tr>
                <td>
                    <input type="button" id="add" value="加"> <input type="button" id="reduce" value="减">
                </td>
                <td>
                    <div id="counter"></div>
                </td>
            </tr>
        </tbody>
    </table>
</body>
</html>
以上代码84行的
var url='';
这里可以自己填要打开的网址。
您的修改应该说是成功的，现在结贴了，把60分给你。不过，您改后的代码仍不实用。首先是，新打开的网页打开后打印选项窗体不出现（当在var url='';里不加地址时打印选项窗体出现，不过打开的页面是空白页）。我按你的意思把原网页上的打印代码复制到此页面里，试了，不行。
新打开的网页为index.html 其打印代码如下：<OBJECT id="WebBrowser" height="0" width="0" classid="CLSID:8856F961-340A-11D0-A96B-00C04FD705A2"
VIEWASTEXT>
</OBJECT> <input onclick="document.all.WebBrowser.ExecWB(6,6)" type="button" id="dayinDiv" style="font-size:28px;  width: 28px; height: 28px; border:0px none" value="打印" ;>