var no = 5; // STAR number　１画面に出る画像の枚数
var speed = 30; // smaller number moves the STAR faster
STAR = new Array();
STAR[0] = "shared/images/matatabi/ha.gif";    // 画像の指定。STAR[?]の数字は0から始まる
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 = 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=\"" + STAR[j] + "\" border=\"0\"></layer>");
} else {
document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src=\"" + STAR[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=\"" + STAR[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=\"" + STAR[j] + "\" border=\"0\"></div>");
}
}
if (j == (STAR.length-1)) { j = 0; } else { j += 1; }
}


function STAR_IE() {  // 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("STAR_IE()", speed);
}

if (ns4up) {
STAR_NS();
} else if (ie4up) {
STAR_IE();
}
