關於櫻花飄落的語法!!!

這以下是關於櫻花飄落的語法，但是請問各位大大
假如你有長一點的頁面 櫻花就無法飄落至最底層 這個程式碼應該怎麼改呢?




var no = 20; // snow number
var speed = 1; // smaller number moves the snow faster
var snowflake1 = "pink1.gif";   ←圖片１（放櫻花就是櫻花的飄落）
var snowflake2 = "pink2.gif"; 　←圖片２（放櫻花就是櫻花的飄落）
var snowflake3 = "pink3.gif"; 　←圖片３（放櫻花就是櫻花的飄落）
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 = 1024, doc_height = 764;
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 = 0; // set coordinate variables
xp = Math.random()*(doc_width-50); // set position variables
yp = Math.random()*doc_height;
am = Math.random()*20; // set amplitude variables
stx = 0.02 + Math.random()/10; // set step variables
sty = 0.7 + Math.random(); // set step variables
if (ns4up) { // set layers
if (i == 0) {
document.write("<layer name=\"dot"+ i +"\" left=\"15\" ");
document.write("top=\"15\" visibility=\"show\"><img src=\"");
document.write(snowflake2 + "\" border=\"0\"></layer>");
} else {
document.write("<layer name=\"dot"+ i +"\" left=\"15\" ");
document.write("top=\"15\" visibility=\"show\"><img src=\"");
document.write(snowflake3 + "\" border=\"0\"></layer>");
}
} else if (ie4up) {
if (i == 0) {
document.write("<div id=\"dot"+ i +"\" style=\"POSITION: ");
document.write("absolute; Z-INDEX: "+ i +"; VISIBILITY: ");
document.write("visible; TOP: 15px; LEFT: 15px;\"><img src=\"");
document.write(snowflake1 + "\" border=\"0\"></div>");
} else {
document.write("<div id=\"dot"+ i +"\" style=\"POSITION: ");
document.write("absolute; Z-INDEX: "+ i +"; VISIBILITY: ");
document.write("visible; TOP: 15px; LEFT: 15px;\"><img src=\"");
document.write(snowflake2 + "\" border=\"0\"></div>");
}
}
}
function snowNS() { // Netscape main animation function
for (i = 0; i < no; ++ i) { // iterate for every dot
yp += sty;
if (yp > doc_height-50) {
xp = Math.random()*(doc_width-am-30);
yp = 0;
stx = 0.02 + Math.random()/10;
sty = 0.7 + Math.random();
doc_width = self.innerWidth;
doc_height = self.innerHeight;
}
dx += stx;
document.layers["dot"+i].top = yp;
document.layers["dot"+i].left = xp + am*Math.sin(dx);
}
setTimeout("snowNS()", speed);
}
function snowIE() { // IE main animation function
for (i = 0; i < no; ++ i) { // iterate for every dot
yp += sty;
if (yp > doc_height-50) {
xp = Math.random()*(doc_width-am-30);
yp = 0;
stx = 0.02 + Math.random()/10;
sty = 0.7 + Math.random();
doc_width = document.body.clientWidth;
doc_height = document.body.clientHeight;
}
dx += stx;
document.all["dot"+i].style.pixelTop = yp;
document.all["dot"+i].style.pixelLeft = xp + am*Math.sin(dx);
}
setTimeout("snowIE()", speed);
}
if (ns4up) {
snowNS();
} else if (ie4up) {
snowIE();
}

最後要加上Script的框框唷

x0