循环不间断向上滚动的文本特效代码

<body background="背影" bgproperties=fixed link="#FF6699" vlink="#FF9999"> <script> <!-- Begin var snowsrc="/images/logo.gif"//图片自选 var no = 11; // snow number var speed = 11; // smaller number moves the snow faster var ns4up = (document.layers) ? 1 : 0; // browser sniffer var ie4up = (document.all) ? 1 : 0; var dx, xp, yp; // coordinate and position variables var am, stx, sty; // amplitude and step variables var i, doc_width = 1000, doc_height = 1200; if (ns4up) { doc_width = self.innerWidth; doc_height = self.innerHeight; } else if (ie4up) { doc_width = document.body.clientWidth; doc_height = document.body.clientHeight; } dx = new Array(); xp = new Array(); yp = new Array(); am = new Array(); stx = new Array(); sty = new Array(); for (i = 0; i < no; ++ i) { dx[i] = 0; // set coordinate variables xp[i] = Math.random()*(doc_width-50); // set position variables yp[i] = Math.random()*doc_height; am[i] = Math.random()*20; // set amplitude variables stx[i] = 0.02 + Math.random()/10; // set step variables sty[i] = 0.7 + Math.random(); // set step variables if (ns4up) { // set layers if (i == 0) { document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src='"+snowsrc+"' border=\"0\"></layer>"); } else { document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src='"+snowsrc+"' border=\"0\"></layer>"); } } else if (ie4up) { if (i == 0) { document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc+"' border=\"0\"></a></div>"); } else { document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc+"' border=\"0\"></div>"); } } } function snowNS() { // Netscape main animation function for (i = 0; i < no; ++ i) { // iterate for every dot yp[i] += sty[i]; if (yp[i] > doc_height-50) { xp[i] = Math.random()*(doc_width-am[i]-30); yp[i] = 0; stx[i] = 0.02 + Math.random()/10; sty[i] = 0.7 + Math.random(); doc_width = self.innerWidth; doc_height = self.innerHeight; } dx[i] += stx[i]; document.layers["dot"+i].top = yp[i]; document.layers["dot"+i].left = xp[i] + am[i]*Math.sin(dx[i]); } setTimeout("snowNS()", 10); } function snowIE() { // IE main animation function for (i = 0; i < no; ++ i) { // iterate for every dot yp[i] += sty[i]; if (yp[i] > doc_height-50) { xp[i] = Math.random()*(doc_width-am[i]-30); yp[i] = 0; stx[i] = 0.02 + Math.random()/10; sty[i] = 0.7 + Math.random(); doc_width = document.body.clientWidth; doc_height = document.body.clientHeight; } dx[i] += stx[i]; document.all["dot"+i].style.pixelTop = yp[i]; document.all["dot"+i].style.pixelLeft = xp[i] + am[i]*Math.sin(dx[i]); } setTimeout("snowIE()", 10); } if (ns4up) { snowNS(); } else if (ie4up) { snowIE(); } </script> </body>