Click on the picture to turn the previous page to the next page. Image special effects

This is the 1st picture

<script> <BR>var zhang=2 <BR>function next(){ <BR>if(zhang==7){ <BR>alert("这已经是最后一张了!") <BR>zhang=6 <BR>} <BR>document.getElementById("tu").src=zhang+".jpg" <BR>text.innerHTML="当前是第"+zhang+"张图片" <BR>zhang++ <BR>} <BR>function up(){ <BR>if(zhang==2){ <BR>alert("这已经是第一张了!") <BR>zhang=3 <BR>} <BR>document.getElementById("tu").src=(zhang-2)+".jpg" <BR>text.innerHTML="当前是第"+(zhang-2)+"张图片" <BR>zhang-- <BR>} <BR></script> <script>// <br><br>var w=document.getElementById("tu").width//500 <BR>var h=document.getElementById("tu").height//400 <BR>document.getElementById("tu").style.width=w <BR>document.getElementById("tu").style.height=h <br><br>//document.getElementById("divleft").style.visibility='hidden' <BR>document.getElementById("divleft").style.width=w/2 <BR>document.getElementById("divleft").style.height=h <BR>document.getElementById("divleft").style.left=0 <br><br>//document.getElementById("divright").style.visibility='hidden' <BR>document.getElementById("divright").style.width=w/2 <BR>document.getElementById("divright").style.height=h <BR>document.getElementById("divright").style.left=w/2 <br><br>//document.write("<style> #tu{width:"+w+"px; height:"+h+"px;z-index:2000}") <br><br>function show_div(id,img){ <BR>document.getElementById(id).innerHTML="<img src="+img+" alt="Click on the picture to turn the previous page to the next page. Image special effects" >" <BR>} <BR>function hide_div(id){ <BR>document.getElementById(id).innerHTML="" <BR>} <BR></script>