var isNS = false, isIE = false, flyDirection = "right", timeoutID
var flyRight = new Image(), flyLeft = new Image()
flyRight.src = "para1.gif"
flyLeft.src  = "para2.gif"
//
function init() {
isNS = (document.layers) ? true : false
isIE = (document.all)    ? true : false
layerRef    = (isNS) ? "document.layers." : "document.all."
styleRef    = (isNS) ? "" : ".style"
leftRef     = (isNS) ? ".left" : ".pixelLeft"
topRef      = (isNS) ? ".top"  : ".pixelTop"
flyGlider()
}
//
function flyGlider() {
clearTimeout(timeoutID)
var gliderPos = eval(layerRef + "gliderDiv" + styleRef + leftRef)
if (flyDirection == "right") {moveRight(gliderPos)}
else {moveLeft(gliderPos)}
timeoutID = setTimeout("flyGlider()",192)
}
//
function moveRight(thePos) {
if (thePos < 600) {eval(layerRef + "gliderDiv" + styleRef + leftRef + " += 15")}
else {changeDirection()}
}
//
function moveLeft(thePos) {
if (thePos > 100) {eval(layerRef + "gliderDiv" + styleRef + leftRef + " += -15")}
else {changeDirection()}
}
//
function changeDirection() {
var gliderImg = (isNS) ? document.gliderDiv.document.images["glider"] : document.all.glider
if (flyDirection == "right") {
flyDirection = "left"
gliderImg.src = flyLeft.src
}
else {
flyDirection = "right"
gliderImg.src = flyRight.src
}
}
//