上飘的背景效果试范点我以下为上飘的背景效果语法复制程式
<body>
<script language="JavaScript1.2">
<!--
var no = 20;
var speed = 2;
var snow = new Array();
snow[0] = "背景图片网址"
snow[1] = "背景图片网址"
var ns4up = (document.layers) ? 1 : 0;
var ie4up = (document.all) ? 1 : 0;
var dx, xp, yp;
var am, stx, sty;
var i, doc_width = 800, doc_height = 1800;
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();
j = 0;
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=\""+ snow[j] + "\" border=\"0\"></layer>");
} else {
document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src=\""+ snow[j] + "\" 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; width:1;\"><img src=\"" + snow[j] + "\" border=\"0\"></div>");
} else {
document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"VISIBILITY: visible; TOP: 15px; LEFT: 15px; width:1;\"><img src=\"" + snow[j] + "\" border=\"0\"></div>");
}
}
if (j == (snow.length-1)) { j = 0; } else { j += 1; }
}
function snowNS() { // Netscape main animation function
for (i = 0; i < no; ++ i) { // iterate for every dot
yp[i] -= sty[i]; if (yp[i] < -50) {
xp[i] = Math.random()*(doc_width-am[i]-30);
yp[i] = doc_height;
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()", speed);
}
function snowIE() { // IE main animation function
for (i = 0; i < no; ++ i) { // iterate for every dot
yp[i] -= sty[i];
if (yp[i] < -50) {
xp[i] = Math.random()*(doc_width-am[i]-30);
yp[i] = doc_height;
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()", speed);
}
if (ns4up) {
snowNS();
} else if (ie4up) {
snowIE();
}
-->
</script>
</body>
