JS implement scroll

html代碼

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >
< html xmlns = "http://www.w3.org/1999/xhtml" >
< head >
< meta http-equiv = "Content-Type" content = "text/html; charset=iso-8859-1" />
< title > Untitled Document </ title >
</ head >
< body >
< img onmouseover = "LeftOver()" onmouseout = "LeftOut()" onmousedown = "LeftDown()" onmouseup = "LeftUp()" src = "right.gif" width = "13" height = "13" /> left
< img onmouseover = "RightOver()" onmouseout = "RightOut()" onmousedown = "RightDown()" onmouseup = "RightUp()" src = "left.gif" width = "13" height = "13" /> right
< DIV id = "scrollBox" style = "Z-INDEX: 100; OVERFLOW: hidden; WIDTH: 490px; POSITION: static; HEIGHT: 170px" >
< TABLE cellSpacing = 0 cellPadding = 0 width = "100%" border = 0 > < TBODY >
< TR >
< TD id = "scrollObject" >
< img id = "pfxx" src = "DSC08410.JPG" width = "1280" height = "960" />
</ TD >
< TD id = "scrollObjectMirror" > </ TD >
</ TR >
</ TBODY > </ TABLE >
</ DIV >
< script src = "scrollpic.js" language = "javascript" > </ script >
</ body >
</ html >

scroll.js 代碼

var speed3=10 //??????????
scrollObjectMirror.innerHTML=scrollObject.innerHTML
function MarqueeLeft(obj,obj1,obj2,step){
if (obj2.offsetWidth-obj.scrollLeft<=0) {
obj.scrollLeft-=obj1.offsetWidth
}
else {
obj.scrollLeft+=step;
}
}
function MarqueeRight(obj,obj1,obj2,step){
if (obj.scrollLeft<=0) {
obj.scrollLeft +=obj1.offsetWidth
}
else {
obj.scrollLeft-=step;
}
}
var MyMar1;
function LeftOut(){clearInterval(MyMar1)}
function LeftOver(){clearInterval(MyMar1);MyMar1=setInterval( "MarqueeLeft(scrollBox, scrollObject, scrollObjectMirror, 1)" ,speed3)}
function RightOut(){clearInterval(MyMar1)}
function RightOver(){clearInterval(MyMar1);MyMar1=setInterval( "MarqueeRight(scrollBox, scrollObject, scrollObjectMirror, 1)" ,speed3)}
//οnmοuseοut="LeftOut()" οnmοusedοwn="LeftDown()" οnmοuseup="LeftUp()"
function LeftUp(){clearInterval(MyMar1);MyMar1=setInterval( "MarqueeLeft(scrollBox, scrollObject, scrollObjectMirror, 1)" ,speed3)}
function LeftDown(){clearInterval(MyMar1);MyMar1=setInterval( "MarqueeLeft(scrollBox, scrollObject, scrollObjectMirror, 5)" ,speed3)}
function RightUp(){clearInterval(MyMar1);MyMar1=setInterval( "MarqueeRight(scrollBox, scrollObject, scrollObjectMirror, 1)" ,speed3)}
function RightDown(){clearInterval(MyMar1);MyMar1=setInterval( "MarqueeRight(scrollBox, scrollObject, scrollObjectMirror, 5)" ,speed3)}