var ewave_scroller = new Class({
options: {
maxThumbSize: 10,
mode: 'vertical',
width: 0,
scrollSteps: 10,
wheel: true,
onScroll: Class.empty,
onPage: Class.empty
},
initialize: function(content, knob, options){
this.setOptions(options);
this.horz = (this.options.mode == "horizontal");
this.content = $(content).setStyle('overflow', 'hidden');
this.knob = $(knob);
this.track = this.knob.getParent();
this.setPositions();
if(this.horz && this.options.width) {
this.wrapper = new Element('div');
this.content.getChildren().each(function(child){
this.wrapper.adopt(child);
});
this.wrapper.injectInside(this.content).setStyle('width', this.options.width);
}

this.bound = {
'start': this.start.bind(this),
'end': this.end.bind(this),
'drag': this.drag.bind(this),
'wheel': this.wheel.bind(this),
'page': this.page.bind(this)
};

this.position = {};
this.mouse = {};
this.update();
this.attach();
var clearScroll = function (){
$clear(this.scrolling);
}.bind(this);
this.knob.addEvent('click', clearScroll.bind(this));
window.addEvent('domready', function(){
try {
$(document.body).addEvent('mouseup', clearScroll.bind(this));
}catch(e){}
}.bind(this));
},
setPositions: function(){
[this.track, this.knob].each(function(el){
if (el.getStyle('position') == 'static') el.setStyle('position','relative');
});
},

update: function(){
var plain = this.horz?'Width':'Height';
this.contentSize = this.content['offset'+plain];
this.contentScrollSize = this.content['scroll'+plain];
this.trackSize = this.track['offset'+plain];
this.contentRatio = this.contentSize / this.contentScrollSize;
this.knobSize = (this.trackSize * this.contentRatio).limit(this.options.maxThumbSize, this.trackSize);
this.scrollRatio = this.contentScrollSize / this.trackSize;
this.knob.setStyle(plain.toLowerCase(), this.knobSize+'px');
this.updateThumbFromContentScroll();
this.updateContentFromThumbPosition();
},

updateContentFromThumbPosition: function(){
this.content[this.horz?'scrollLeft':'scrollTop'] = this.position.now * this.scrollRatio;
},

updateThumbFromContentScroll: function(){
this.position.now = (this.content[this.horz?'scrollLeft':'scrollTop'] / this.scrollRatio).limit(0, (this.trackSize - this.knobSize));
this.knob.setStyle(this.horz?'left':'top', this.position.now+'px');
},

attach: function(){
this.knob.addEvent('mousedown', this.bound.start);
if (this.options.scrollSteps) this.content.addEvent('mousewheel', this.bound.wheel);
this.track.addEvent('mouseup', this.bound.page);
},

wheel: function(event){
event = new Event(event);
this.scroll(-(event.wheel * this.options.scrollSteps));
this.updateThumbFromContentScroll();
event.stop();
},

scroll: function(steps){
steps = steps||this.options.scrollSteps;
this.content[this.horz?'scrollLeft':'scrollTop'] += steps;
this.updateThumbFromContentScroll();
},
forward: function(steps){
this.scroll(steps);
},
back: function(steps){
steps = steps||this.options.scrollSteps;
this.scroll(-steps);
},

page: function(event){
var axis = this.horz?'x':'y';
event = new Event(event);
var forward = (event.page[axis] > this.knob.getPosition()[axis]);
this.scroll((forward?1:-1)*this.content['offset'+(this.horz?'Width':'Height')]);
this.updateThumbFromContentScroll();
this.fireEvent('onPage', forward);
event.stop();
},

start: function(event){
event = new Event(event);
var axis = this.horz?'x':'y';
this.mouse.start = event.page[axis];
this.position.start = this.knob.getStyle(this.horz?'left':'top').toInt();
document.addEvent('mousemove', this.bound.drag);
document.addEvent('mouseup', this.bound.end);
this.knob.addEvent('mouseup', this.bound.end);
event.stop();
},

end: function(event){
event = new Event(event);
document.removeEvent('mousemove', this.bound.drag);
document.removeEvent('mouseup', this.bound.end);
this.knob.removeEvent('mouseup', this.bound.end);
event.stop();
},

drag: function(event){
event = new Event(event);
var axis = this.horz?'x':'y';
this.mouse.now = event.page[axis];
this.position.now = (this.position.start + (this.mouse.now - this.mouse.start)).limit(0, (this.trackSize - this.knobSize));
this.updateContentFromThumbPosition();
this.updateThumbFromContentScroll();
event.stop();
}
});
ewave_scroller.implement(new Events);
ewave_scroller.implement(new Options);

function updatescroll(){
new ewave_scroller('content', 'scroll_container');
var settop = new Fx.Style('scroll_container', 'top');
settop.set(0);
var adjust = $('scroll_container').getStyle('height').toInt();
function changeheight(){
$('scroll_container').setStyle('height', adjust - 5)
};
changeheight();
}
window.addEvent('load', function(){
new ewave_scroller('content', 'scroll_container');
var adjust = $('scroll_container').getStyle('height').toInt();
function changeheight(){
$('scroll_container').setStyle('height', adjust - 5)
};
changeheight();
});