状态栏跑马灯效果

<!--
function statusMessageObject(p,d) {
this.msg = MESSAGE
this.out = " "
this.pos = POSITION
this.delay = DELAY
this.i = 0
this.reset = clearMessage
}
function clearMessage() {
this.pos = POSITION
}
var POSITION = 100
var DELAY = 50 //在此设置文字速度//
var MESSAGE = "欢迎使用自助建站2004最新版 "
var scroll = new statusMessageObject()
function scroller() {
for (scroll.i = 0; scroll.i < scroll.pos; scroll.i++) {
scroll.out += " "
}
if (scroll.pos >= 0)
scroll.out += scroll.msg
else scroll.out = scroll.msg.substring(-scroll.pos,scroll.msg.length)
window.status = scroll.out
scroll.out = " "
scroll.pos--
if (scroll.pos < -(scroll.msg.length)) {
scroll.reset()
}
setTimeout ('scroller()',scroll.delay)
}
function snapIn(jumpSpaces,position) {
var msg = scroll.msg
var out = ""
for (var i=0; i<position; i++)
{out += msg.charAt(i)}
for (i=1;i<jumpSpaces;i++)
{out += " "}
out += msg.charAt(position)
window.status = out
if (jumpSpaces <= 1) {
position++
if (msg.charAt(position) == ' ')
{position++ }
jumpSpaces = 100-position
} else if (jumpSpaces > 3)
{jumpSpaces *= .75}
else
{jumpSpaces--}
if (position != msg.length) {
var cmd = "snapIn(" + jumpSpaces + "," + position + ")";
scrollID = window.setTimeout(cmd,scroll.delay);
} else {
window.status=""
jumpSpaces=0
position=0
cmd = "snapIn(" + jumpSpaces + "," + position + ")";
scrollID = window.setTimeout(cmd,scroll.delay);
return false
}
return true
}
snapIn(100,0);
// -->