I'm trying to create my own style custom horizontal scrollbar...
For I want is change this code to Horizontal Scrolling only,,,,but I can't find to correct these codes
Thanks for any idea!!!

Here css code:
body {
background:#eee;
margin:0;
padding:0;
}

.example {
-moz-border-radius:3px;
-webkit-border-radius:3px;
background:#FFF;
border:1px #000 solid;
height:600px;
margin:20px auto;
padding:15px;
position:relative;
width:800px;
}

#main_content {
height:50%;
left:5%;
overflow:auto;
position:absolute;
top:5%;
width:90%;
}

.ssb_down {
background:transparent url(../images/icon-arrow-down.png);
bottom:0;
cursorointer;
position:absolute;
right:0;
}

.ssb_sb {
background:transparent url(../images/middle.png);
cursorointer;
position:absolute;
right:0;
}

.ssb_sb_down {
background:transparent url(../images/middrag.png);
}

.ssb_sb_over {
background:transparent url(../images/midhover.png);
}

.ssb_st {
background:transparent url(../images/back.png);
cursorointer;
height:100%;
position:absolute;
right:0;
top:0;
}

.ssb_up {
background:transparent url(../images/icon-arrow-up.png);
cursorointer;
position:absolute;
right:0;
top:0;
}

.parent {
font-family:verdana;
height:100%;
padding:10px;
position:relative;
}

Here JS code:
var ssb = {
aConts : [],
mouseY : 0,
N : 0,
asd : 0, /*active scrollbar element*/
sc : 0,
sp : 0,
to : 0,

// constructor
scrollbar : function (cont_id) {
var cont = document.getElementById(cont_id);

// perform initialization
if (! ssb.init()) return false;

var cont_clone = cont.cloneNode(false);
cont_clone.style.overflow = "hidden";
cont.parentNode.appendChild(cont_clone);
cont_clone.appendChild(cont);
cont.style.position = 'absolute';
cont.style.left = cont.style.top = '0px';
cont.style.width = cont.style.height = '100%';

// adding new container into array
ssb.aConts[ssb.N++] = cont;

cont.sg = false;

//creating scrollbar child elements
cont.st = this.create_div('ssb_st', cont, cont_clone);
cont.sb = this.create_div('ssb_sb', cont, cont_clone);
cont.su = this.create_div('ssb_up', cont, cont_clone);
cont.sd = this.create_div('ssb_down', cont, cont_clone);

// on mouse down processing
cont.sb.onmousedown = function (e) {
if (! this.cont.sg) {
if (! e) e = window.event;

ssb.asd = this.cont;
this.cont.yZ = e.screenY;
this.cont.sZ = cont.scrollTop;
this.cont.sg = true;

// new class name
this.className = 'ssb_sb ssb_sb_down';
}
return false;
}
// on mouse down on free track area - move our scroll element too
cont.st.onmousedown = function (e) {
if (! e) e = window.event;
ssb.asd = this.cont;

ssb.mouseY = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;
for (var o = this.cont, y = 0; o != null; o = o.offsetParent) y += o.offsetTop;
this.cont.scrollTop = (ssb.mouseY - y - (this.cont.ratio * this.cont.offsetHeight / 2) - this.cont.sw) / this.cont.ratio;
this.cont.sb.onmousedown(e);
}

// onmousedown events
cont.su.onmousedown = cont.su.ondblclick = function (e) { ssb.mousedown(this, -1); return false; }
cont.sd.onmousedown = cont.sd.ondblclick = function (e) { ssb.mousedown(this, 1); return false; }

//onmouseout events
cont.su.onmouseout = cont.su.onmouseup = ssb.clear;
cont.sd.onmouseout = cont.sd.onmouseup = ssb.clear;

// on mouse over - apply custom class name: ssb_sb_over
cont.sb.onmouseover = function (e) {
if (! this.cont.sg) this.className = 'ssb_sb ssb_sb_over';
return false;
}

// on mouse out - revert back our usual class name 'ssb_sb'
cont.sb.onmouseout = function (e) {
if (! this.cont.sg) this.className = 'ssb_sb';
return false;
}

// onscroll - change positions of scroll element
cont.ssb_onscroll = function () {
this.ratio = (this.offsetHeight - 2 * this.sw) / this.scrollHeight;
this.sb.style.top = Math.floor(this.sw + this.scrollTop * this.ratio) + 'px';
}

// scrollbar width
cont.sw = 20;

// start scrolling
cont.ssb_onscroll();
ssb.refresh();

// binding own onscroll event
cont.onscroll = cont.ssb_onscroll;
return cont;
},

// initialization
init : function () {
if (window.oper || (! window.addEventListener && ! window.attachEvent)) { return false; }

// temp inner function for event registration
function addEvent (o, e, f) {
if (window.addEventListener) { o.addEventListener(e, f, false); ssb.w3c = true; return true; }
if (window.attachEvent) return o.attachEvent('on' + e, f);
return false;
}

// binding events
addEvent(window.document, 'mousemove', ssb.onmousemove);
addEvent(window.document, 'mouseup', ssb.onmouseup);
addEvent(window, 'resize', ssb.refresh);
return true;
},

// create and append div finc
create_div : function(c, cont, cont_clone) {
var o = document.createElement('div');
o.cont = cont;
o.className = c;
cont_clone.appendChild(o);
return o;
},
// do clear of controls
clear : function () {
clearTimeout(ssb.to);
ssb.sc = 0;
return false;
},
// refresh scrollbar
refresh : function () {
for (var i = 0, N = ssb.N; i < N; i++) {
var o = ssb.aConts[i];
o.ssb_onscroll();
o.sb.style.width = o.st.style.width = o.su.style.width = o.su.style.height = o.sd.style.width = o.sd.style.height = o.sw + 'px';
o.sb.style.height = Math.ceil(Math.max(o.sw * .5, o.ratio * o.offsetHeight) + 1) + 'px';
}
},
// arrow scrolling
arrow_scroll : function () {
if (ssb.sc != 0) {
ssb.asd.scrollTop += 6 * ssb.sc / ssb.asd.ratio;
ssb.to = setTimeout(ssb.arrow_scroll, ssb.sp);
ssb.sp = 32;
}
},

/* event binded functions : */
// scroll on mouse down
mousedown : function (o, s) {
if (ssb.sc == 0) {
// new class name
o.cont.sb.className = 'ssb_sb ssb_sb_down';
ssb.asd = o.cont;
ssb.sc = s;
ssb.sp = 400;
ssb.arrow_scroll();
}
},
// on mouseMove binded event
onmousemove : function(e) {
if (! e) e = window.event;
// get vertical mouse position
ssb.mouseY = e.screenY;
if (ssb.asd.sg) ssb.asd.scrollTop = ssb.asd.sZ + (ssb.mouseY - ssb.asd.yZ) / ssb.asd.ratio;
},
// on mouseUp binded event
onmouseup : function (e) {
if (! e) e = window.event;
var tg = (e.target) ? e.target : e.srcElement;
if (ssb.asd && document.releaseCapture) ssb.asd.releaseCapture();

// new class name
if (ssb.asd) ssb.asd.sb.className = (tg.className.indexOf('scrollbar') > 0) ? 'ssb_sb ssb_sb_over' : 'ssb_sb';
document.onselectstart = '';
ssb.clear();
ssb.asd.sg = false;
}
}

window.onload = function() {
ssb.scrollbar('main_content'); // scrollbar initialization
}

Here html code:
<div id="main_content">
<iframe src="#.html"scrolling="no"></iframe>
</div>