var number =6
var speed = 50
var maximg =2
var act = new Array(),positionX = new Array(),positionY = new Array()
var moveX = new Array(),moveY = new Array()
var j = maximg
img = new Array()
img[0] = "pic/1941.gif"
img[1] = "pic/1942.gif"
img[2] = "pic/1943.gif"


for (var i = 0; i < number ;++ i) {
act[i] = 0 
positionX[i] = Math.random()*document.body.clientWidth-50
positionY[i] = Math.random()*document.body.clientHeight
moveX[i] = 0.1 + Math.random()/100
moveY[i] = 0.1 + Math.random()*3
if (i == 0) 
{
document.write("<div id=\"fly"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible\"><img src=\"" + img[j] + "\" border=\"0\"></div>")}
else {
document.write("<div id=\"fly"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible\"><img src=\"" + img[j] + "\" border=\"0\"></div>")}
if (j == 0) { j = maximg }
else { j -= 1 }
}
function gofly() { 
for (var i = 0; i < number ;++ i) { // iterate for every fly
positionY[i] -= moveY[i]
act[i] += moveX[i]
document.all["fly"+i].style.pixelTop = positionY[i]+ Math.cos(act[i])*positionY[i]/15
document.all["fly"+i].style.pixelLeft = positionX[i] + Math.sin(act[i])*positionX[i]/50
if (positionY[i] < 0) {
moveX[i] = 0.1+ Math.random()/100
moveY[i] = 0.1 + Math.random()*3
positionX[i] = Math.random()*document.body.clientWidth-50
positionY[i] = document.body.clientHeight
}
}
setTimeout("gofly()", speed)
}
gofly()