<span id="ContentArea"><p>把如下代码复制到<body>与</body>之间</p> <p><s cript language=Javas cript><br /> <!-- Beginning of Javas cript -<br /> var x,y<br /> var marginbottom<br /> var marginleft=0<br /> var margintop=0<br /> var marginright<br /> var cliptop<br /> var clipbottom<br /> var clipleft<br /> var clipright<br /> var clippoints</p> <p> </p> <p>var ballheight=150</p> <p>var ballwidth=150</p> <p> </p> <p>var imageheight=525</p> <p>var imagewidth=457</p> <p> </p> <p> </p> <p>// less is faster</p> <p>var tempo=25</p> <p> </p> <p>// horizontal move (pixels) within time unit</p> <p>var stepx=12</p> <p> </p> <p>// vertical move (pixels) within time unit</p> <p>var stepy=6</p> <p>var timer</p> <p> </p> <p> </p> <p>// check the width and the height of the document</p> <p>// gets the starting position of the ball by random</p> <p>function setValues() {</p> <p> if (document.all) {</p> <p> marginbottom = imageheight-ballheight</p> <p> marginright = imagewidth-ballwidth</p> <p> document.all.ball.style.posLeft=randommaker(400)</p> <p> document.all.ball.style.posTop=0</p> <p> document.all.textcontent.style.posLeft=0</p> <p> document.all.textcontent.style.posTop=0</p> <p> document.all.ball.style.filter="alpha(opacity=0,finishopacity=100,style=2,startX=0px,startY=0px,finishX=100px,finishY=100px)"</p> <p> moveball()</p> <p> }</p> <p>}</p> <p> </p> <p>// randomfunction</p> <p>function randommaker(range) { </p> <p> rand=Math.floor(range*Math.random())</p> <p> return rand</p> <p>}</p> <p> </p> <p>function moveball() {</p> <p> checkposition()</p> <p> if (document.all) { </p> <p> document.all.ball.style.posLeft+=stepx</p> <p> document.all.ball.style.posTop+=stepy</p> <p> </p> <p> cliptop=document.all.ball.style.posTop</p> <p> clipbottom=cliptop+ballheight</p> <p> clipleft=document.all.ball.style.posLeft</p> <p> clipright=clipleft+ballwidth</p> <p> </p> <p> clippoints="rect("+cliptop+" "+clipright+" "+clipbottom+" "+clipleft+")"</p> <p> document.all.textcontent.style.clip=clippoints</p> <p> timer=setTimeout("moveball()",tempo)</p> <p> }</p> <p>}</p> <p> </p> <p>function checkposition() {</p> <p> if (document.all) {</p> <p> if (document.all.ball.style.posLeft>=marginright) {</p> <p> stepx=stepx*-1</p> <p> document.all.ball.style.posLeft-=10</p> <p> }</p> <p> if (document.all.ball.style.posLeft<=marginleft) {</p> <p> stepx=stepx*-1</p> <p> document.all.ball.style.posLeft+=10</p> <p> } </p> <p> if (document.all.ball.style.posTop>=marginbottom) {</p> <p> stepy=stepy*-1</p> <p> document.all.ball.style.posTop-=10</p> <p> }</p> <p> if (document.all.ball.style.posTop<=margintop) {</p> <p> stepy=stepy*-1</p> <p> document.all.ball.style.posTop+=10</p> <p> }</p> <p> }</p> <p>}</p> <p>// - End of Javas cript - --></p> <p></s cript></p> <p><span id=textcontent style="LEFT: -5000px; POSITION: absolute; TOP: -5000px"><IMG</p> <p>border=0 src="Computer_WindowsXP_01_032.jpg"> </span></p> <p><span id=ball</p> <p>style="BACKGROUND-COLOR: white; HEIGHT: 150px; POSITION: absolute; TOP: -50px; WIDTH: 150px"></span><br /> 修改<body>标签为</p> <p><body onload=setValues()></p></span>
