一个较好的弹出日历，在输入表单框时选择日历

<script language=javascript>
var DS_x,DS_y;
function dateSelector() //构造dateSelector对象，用来实现一个日历形式的日期输入框。
{
var myDate=new Date();
this.year=myDate.getFullYear(); //定义year属性，年份，默认值为当前系统年份。
this.month=myDate.getMonth()+1; //定义month属性，月份，默认值为当前系统月份。
this.date=myDate.getDate(); //定义date属性，日，默认值为当前系统的日。
this.inputName=''; //定义inputName属性，即输入框的name，默认值为空。注意：在同一页中出现多个日期输入框，不能有重复的name！
this.display=display; //定义display方法，用来显示日期输入框。
}
function display() //定义dateSelector的display方法，它将实现一个日历形式的日期选择框。
{
var week=new Array('日','一','二','三','四','五','六');
document.write("<style type=text/css>");
document.write(" .ds_font td,span { font: normal 12px 宋体; color: #000000; }");
document.write(" .ds_border { border: 1px solid #000000; cursor: hand; background-color: #DDDDDD }");
document.write(" .ds_border2 { border: 1px solid #000000; cursor: hand; background-color: #DDDDDD }");
document.write("</style>");
document.write("<input class='text1' size='10' style='text-align:center;' id='DS_"+this.inputName+"' name='"+this.inputName+"' value='"+this.year+"-"+this.month+"-"+this.date+"' title=双击可进行编缉 ondblclick='this.readOnly=false;this.focus()' onblur='this.readOnly=true' readonly>");
document.write("<button style='width:60px;height:18px;font-size:12px;margin:1px;border:1px solid #A4B3C8;background-color:#DFE7EF;' type=button onclick=this.nextSibling.style.display='block' onfocus=this.blur()>选择日期</button>");
document.write("<div style='position:absolute;display:none;text-align:center;width:0px;height:0px;overflow:visible' onselectstart='return false;'>");
document.write(" <div style='position:absolute;left:-60px;top:20px;width:142px;height:165px;background-color:#F6F6F6;border:1px solid #245B7D;' class=ds_font>");
document.write(" <table cellpadding=0 cellspacing=1 width=140 height=20 bgcolor=#CEDAE7 onmousedown='DS_x=event.x-parentNode.style.pixelLeft;DS_y=event.y-parentNode.style.pixelTop;setCapture();' onmouseup='releaseCapture();' onmousemove='dsMove(this.parentNode)' style='cursor:move;'>");
document.write(" <tr align=center>");
document.write(" <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=subYear(this) title='减小年份'><<</td>");
document.write(" <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=subMonth(this) title='减小月份'><</td>");
document.write(" <td width=52%><b>"+this.year+"</b><b>年</b><b>"+this.month+"</b><b>月</b></td>");
document.write(" <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=addMonth(this) title='增加月份'>></td>");
document.write(" <td width=12% onmouseover=this.className='ds_border' onmouseout=this.className='' onclick=addYear(this) title='增加年份'>>></td>");
document.write(" </tr>");
document.write(" </table>");
document.write(" <table cellpadding=0 cellspacing=0 width=140 height=20 onmousedown='DS_x=event.x-parentNode.style.pixelLeft;DS_y=event.y-parentNode.style.pixelTop;setCapture();' onmouseup='releaseCapture();' onmousemove='dsMove(this.parentNode)' style='cursor:move;'>");
document.write(" <tr align=center>");
for(i=0;i<7;i++)
document.write(" <td>"+week[i]+"</td>");
document.write(" </tr>");
document.write(" </table>");
document.write(" <table cellpadding=0 cellspacing=2 width=140 bgcolor=#EEEEEE>");
for(i=0;i<6;i++)
{
document.write(" <tr align=center>");
for(j=0;j<7;j++)
document.write(" <td width=10% height=16 onmouseover=if(this.innerText!=''&&this.className!='ds_border2')this.className='ds_border' onmouseout=if(this.className!='ds_border2')this.className='' onclick=getValue(this,document.all('DS_"+this.inputName+"'))></td>");
document.write(" </tr>");
}
document.write(" </table>");
document.write(" <span style=cursor:hand onclick=this.parentNode.parentNode.style.display='none'>【关闭】</span>");
document.write(" </div>");
document.write("</div>");
dateShow(document.all("DS_"+this.inputName).nextSibling.nextSibling.childNodes[0].childNodes[2],this.year,this.month)
}
function subYear(obj) //减小年份
{
var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
myObj[0].innerHTML=eval(myObj[0].innerHTML)-1;
dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}
function addYear(obj) //增加年份
{
var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
myObj[0].innerHTML=eval(myObj[0].innerHTML)+1;
dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}
function subMonth(obj) //减小月份
{
var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
var month=eval(myObj[2].innerHTML)-1;
if(month==0)
{
month=12;
subYear(obj);
}
myObj[2].innerHTML=month;
dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}
function addMonth(obj) //增加月份
{
var myObj=obj.parentNode.parentNode.parentNode.cells[2].childNodes;
var month=eval(myObj[2].innerHTML)+1;
if(month==13)
{
month=1;
addYear(obj);
}
myObj[2].innerHTML=month;
dateShow(obj.parentNode.parentNode.parentNode.nextSibling.nextSibling,eval(myObj[0].innerHTML),eval(myObj[2].innerHTML))
}
function dateShow(obj,year,month) //显示各月份的日
{
var myDate=new Date(year,month-1,1);
var today=new Date();
var day=myDate.getDay();
var selectDate=obj.parentNode.parentNode.previousSibling.previousSibling.value.split('-');
var length;
switch(month)
{
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
length=31;
break;
case 4:
case 6:
case 9:
case 11:
length=30;
break;
case 2:
if((year%4==0)&&(year%100!=0)||(year%400==0))
length=29;
else
length=28;
}
for(i=0;i<obj.cells.length;i++)
{
obj.cells[i].innerHTML='';
obj.cells[i].style.color='';
obj.cells[i].className='';
}
for(i=0;i<length;i++)
{
obj.cells[i+day].innerHTML=(i+1);
if(year==today.getFullYear()&&(month-1)==today.getMonth()&&(i+1)==today.getDate())
obj.cells[i+day].style.color='red';
if(year==eval(selectDate[0])&&month==eval(selectDate[1])&&(i+1)==eval(selectDate[2]))
obj.cells[i+day].className='ds_border2';
}
}
function getValue(obj,inputObj) //把选择的日期传给输入框
{
var myObj=inputObj.nextSibling.nextSibling.childNodes[0].childNodes[0].cells[2].childNodes;
if(obj.innerHTML)
inputObj.value=myObj[0].innerHTML+"-"+myObj[2].innerHTML+"-"+obj.innerHTML;
inputObj.nextSibling.nextSibling.style.display='none';
for(i=0;i<obj.parentNode.parentNode.parentNode.cells.length;i++)
obj.parentNode.parentNode.parentNode.cells[i].className='';
obj.className='ds_border2'
}
function dsMove(obj) //实现层的拖移
{
if(event.button==1)
{
var X=obj.clientLeft;
var Y=obj.clientTop;
obj.style.pixelLeft=X+(event.x-DS_x);
obj.style.pixelTop=Y+(event.y-DS_y);
}
}
</script>
从
<script language=javascript>
var myDate=new dateSelector();
myDate.year--;
myDate.inputName='start_date'; //注意这里设置输入框的name，同一页中日期输入框，不能出现重复的name。
myDate.display();
</script>  到
<script language=javascript>
myDate.year++;
myDate.inputName='end_date'; //注意这里设置输入框的name，同一页中的日期输入框，不能出现重复的name。
myDate.display();
</script>