常见JS demo 亲测

<script type=text/javascript src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js" /></script>



  //google jquery





onclick="event.returnValue=false;"   //禁用checkbox 火狐无效



encodeURIComponent()     JS中文URL编码 utf8



function addFav(t) {document.write('<a href="'+window.location.href+'" title="'+document.title+'" rel="sidebar" onclick="window.external.addFavorite(this.href, this.title);return false;">'+t+'</a>');}

//收藏



<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>

<script language="JavaScript" type="text/javascript" src="/templets/default/bcc/js/jquery.countdown.min.js"></script>

          <script>

                              var liftoffTime456 = new Date("2011/04/20 11:14:56");

                              var serverdate = new Date("2011/04/21 11:14:56");

                              var localdate = new Date();

                              var jtime = localdate - serverdate;

                             // liftoffTime456.setUTCSeconds(liftoffTime456.getUTCSeconds() + Math.round(jtime / 1000));

                              alert(jtime);

                              $(function() {

                              $('#aa').countdown({ alwaysExpire: true, layout: '{hnn}{sep}{mnn}{sep}{snn}', until: liftoffTime456, format: 'HMS', timezone: +8, onExpiry: function() { liftOff('456') } });

                          });

          </script>

<span id="aa"></span>



   //js 倒计时





    $(function(){

        $('#leftmenu a').click(function(){

            $('#leftmenu a').each(function() {

                $(this).removeClass('tabon');

            });

            $(this).addClass('tabon');

        });

    })

       //li选择器





onclick="document.forms['alipaysubmit'].submit();"

      //图片提交



function ShowPic(file,img,imgname) {

    var fileobj = document.getElementById(file);

    var imgobj = document.getElementById(img);

    fileobj.value = imgname.value;

    if(imgname.files){

         if(imgobj)imgobj.src = imgname.files[0].getAsDataURL();   //火狐

    } else {

        if(imgobj){

            imgobj.style.display = "none";           //IE

            document.getElementById(img+"_div").filters.item("DXImageTransform.Microsoft.AlphaImageLoader").src = imgname.value;

            document.getElementById(img+"_div").filters.item("DXImageTransform.Microsoft.AlphaImageLoader").sizingMethod='scale';

        }

    }

}   





===实例===



<div  id="picnamediv_div" style="FILTER:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=image);width:160px; height:120px; display:block; overflow:hidden; display:inline; float:left;">

             <?php

          echo eip_image(eip_href_link('upload/none1.png'),'','160','120','id="picnamediv"  name="picnamediv"');

          ?>

</div>









   //上传图片预览      







"星期" + "日一二三四五六".split("")[new Date("2011/2/2").getDay()]

  //JS判断时间





<script language="javascript" type="text/javascript"> 

function DrawImage(ImgD,FitWidth,FitHeight) 

{ 

var image=new Image(); 

image.src="http://java.ccidnet.com/art/3539/20080625/ImgD.src;"  

    if(image.width>0 && image.height>0) 

    { 

        if(image.width/image.height>= FitWidth/FitHeight) { 

            if(image.width>FitWidth) 

            { 

                ImgD.width=FitWidth; 

                ImgD.height=(image.height*FitWidth)/image.width; 

            } 

            else 

            { 

                ImgD.width=image.width; 

                ImgD.height=image.height; 

            } 

        } else { 

            if(image.height>FitHeight) 

            { 

                ImgD.height=FitHeight; 

                ImgD.width=(image.width*FitHeight)/image.height; 

            } 

            else 

            { 

                ImgD.width=image.width; 

                ImgD.height=image.height; 

            } 

        } 

    } 

} 

<script> 





   //缩略图





<script type=text/javascript src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js" /></script>

<script>

$(function(){

    $("<div>",{

          id: 'test',

          text: 'this is a test',

          "class": "test",

          click: function(){

             $(this).toggleClass('test');

       }

     }).appendTo("body"); 

})

</script> 

   //自动生成



<iframe src="" style="width:800px;height:536px;top:0px;left:0px;position:absolute;visibility:inherit;z-index:-1;" frameborder=0>
</iframe>  



遮挡SELECT

只要在层里面加上下面代码就可以了~

<iframe src="" style="width:800px;height:536px;top:0px;left:0px;position:absolute;visibility:inherit;z-index:-1;" frameborder=0>
</iframe>