function dw_scrollObj(wndoId, lyrId, horizId) {
    var wn = document.getElementById(wndoId);
    this.id = wndoId; dw_scrollObj.col[this.id] = this;
    this.animString = "dw_scrollObj.col." + this.id;
    this.load(lyrId, horizId);
    
    if (wn.addEventListener) {
        wn.addEventListener('DOMMouseScroll', dw_scrollObj.doOnMouseWheel, false);
    } 
    wn.onmousewheel = dw_scrollObj.doOnMouseWheel;
}

dw_scrollObj.printEnabled = false;

dw_scrollObj.defaultSpeed = dw_scrollObj.prototype.speed = 75;
dw_scrollObj.defaultSlideDur = dw_scrollObj.prototype.slideDur = 500;

dw_scrollObj.isSupported = function () {
    if ( document.getElementById && document.getElementsByTagName 
         && document.addEventListener || document.attachEvent ) {
        return true;
    }
    return false;
}

dw_scrollObj.col = {};

dw_scrollObj.prototype.on_load = function() {}
dw_scrollObj.prototype.on_scroll = function() {}
dw_scrollObj.prototype.on_scroll_start = function() {}
dw_scrollObj.prototype.on_scroll_stop = function() {}
dw_scrollObj.prototype.on_scroll_end = function() {}
dw_scrollObj.prototype.on_update = function() {}

dw_scrollObj.prototype.on_glidescroll = function() {}
dw_scrollObj.prototype.on_glidescroll_start = function() {}
dw_scrollObj.prototype.on_glidescroll_stop = function() {}
dw_scrollObj.prototype.on_glidescroll_end = function() {}

dw_scrollObj.prototype.load = function(lyrId, horizId) {
    var wndo, lyr;
    if (this.lyrId) {
        lyr = document.getElementById(this.lyrId);
        lyr.style.visibility = "hidden";
    }
    this.lyr = lyr = document.getElementById(lyrId);
    if ( !dw_scrollObj.printEnabled ) {
        this.lyr.style.position = 'absolute'; 
    }
    this.lyrId = lyrId; 
    this.horizId = horizId || null;
    wndo = document.getElementById(this.id);
    this.y = 0; this.x = 0; this.shiftTo(0,0);
    this.getDims(wndo, lyr); 
    lyr.style.visibility = "visible";
    this.ready = true; this.on_load(); 
}

dw_scrollObj.prototype.shiftTo = function(x, y) {
    if (this.lyr) {
        this.lyr.style.left = (this.x = x) + "px"; 
        this.lyr.style.top = (this.y = y) + "px";
    }
}

dw_scrollObj.prototype.getX = function() { return this.x; }
dw_scrollObj.prototype.getY = function() { return this.y; }

dw_scrollObj.prototype.getDims = function(wndo, lyr) { 
    this.wd = this.horizId? document.getElementById( this.horizId ).offsetWidth: lyr.offsetWidth;
    this.maxX = (this.wd - wndo.offsetWidth > 0)? this.wd - wndo.offsetWidth: 0;
    this.maxY = (lyr.offsetHeight - wndo.offsetHeight > 0)? lyr.offsetHeight - wndo.offsetHeight: 0;
}

dw_scrollObj.prototype.initScrollVals = function(deg, speed) {
    if (!this.ready) return; 
    if (this.timerId) {
        clearInterval(this.timerId); this.timerId = 0;
    }
    this.speed = speed || dw_scrollObj.defaultSpeed;
    this.fx = (deg == 0)? -1: (deg == 180)? 1: 0;
    this.fy = (deg == 90)? 1: (deg == 270)? -1: 0;
    this.endX = (deg == 90 || deg == 270)? this.x: (deg == 0)? -this.maxX: 0; 
    this.endY = (deg == 0 || deg == 180)? this.y: (deg == 90)? 0: -this.maxY;
    this.lyr = document.getElementById(this.lyrId);
    this.lastTime = new Date().getTime();
    this.on_scroll_start(this.x, this.y);  
    this.timerId = setInterval(this.animString + ".scroll()", 10);    
}

dw_scrollObj.prototype.scroll = function() {
    var now = new Date().getTime();
    var d = (now - this.lastTime)/1000 * this.speed;
    if (d > 0) { 
        var x = this.x + Math.round(this.fx * d); var y = this.y + Math.round(this.fy * d);
        if ( ( this.fx == -1 && x > -this.maxX ) || ( this.fx == 1 && x < 0 ) || 
                ( this.fy == -1 && y > -this.maxY ) || ( this.fy == 1 && y < 0 ) ) 
       {
            this.lastTime = now;
            this.shiftTo(x, y);
            this.on_scroll(x, y);
        } else {
            clearInterval(this.timerId); this.timerId = 0;
            this.shiftTo(this.endX, this.endY);
            this.on_scroll(this.endX, this.endY);
            this.on_scroll_end(this.endX, this.endY);
        }
    }
}

dw_scrollObj.prototype.ceaseScroll = function() {
    if (!this.ready) return;
    if (this.timerId) {
        clearInterval(this.timerId); this.timerId = 0; 
    }
    this.on_scroll_stop(this.x, this.y); 
}

dw_scrollObj.doOnMouseWheel = function(e) {
    var delta = 0;
    if (!e) e = window.event;
    if (e.wheelDelta) { 
        delta = e.wheelDelta/120;
        if (window.opera) delta = -delta;
    } else if (e.detail) { 
        delta = -e.detail/3;
    }
    if (delta) {
        dw_scrollObj.handleMouseWheel(this.id, delta);
    }
    if (e.preventDefault) e.preventDefault();
    e.returnValue = false;
}

dw_scrollObj.prototype.setUpLoadLinks = function(controlsId) {
    var wndoId = this.id; var el = document.getElementById(controlsId); 
    var links = el.getElementsByTagName('a');
    var cls, parts;
    for (var i=0; links[i]; i++) {
        cls = dw_scrollObj.get_DelimitedClass( links[i].className );
        parts = cls.split('_');
        if ( parts[0] == 'load' && parts[1] == wndoId && parts.length > 2 ) {

            var lyrId = parts[2]; var horizId = parts[3]? parts[3]: null;
            dw_Event.add( links[i], 'click', function (wndoId, lyrId, horizId) {
                return function (e) {
                    dw_scrollObj.col[wndoId].load(lyrId, horizId);
                    if (e && e.preventDefault) e.preventDefault();
                    return false;
                }
            }(wndoId, lyrId, horizId) );
        }
    }
}

dw_scrollObj.prototype.setUpScrollControls = function(controlsId, autoHide, axis) {
    var wndoId = this.id; var el = document.getElementById(controlsId); 
    if ( autoHide && axis == 'v' || axis == 'h' ) {
        dw_scrollObj.handleControlVis(controlsId, wndoId, axis);
        dw_Scrollbar_Co.addEvent( this, 'on_load', function() { dw_scrollObj.handleControlVis(controlsId, wndoId, axis); } );
        dw_Scrollbar_Co.addEvent( this, 'on_update', function() { dw_scrollObj.handleControlVis(controlsId, wndoId, axis); } );
    }
    
    var links = el.getElementsByTagName('a'), cls, eType;
    for (var i=0; links[i]; i++) { 
        cls = dw_scrollObj.get_DelimitedClass( links[i].className );
        eType = dw_scrollObj.getEv_FnType( cls.slice(0, cls.indexOf('_') ) );
        switch ( eType ) {
            case 'mouseover' :
            case 'mousedown' :
                dw_scrollObj.handleMouseOverDownLinks(links[i], wndoId, cls);
                break;
            case 'scrollToId': 
                dw_scrollObj.handleScrollToId(links[i], wndoId, cls);
                break;
            case 'scrollTo' :
            case 'scrollBy':
            case 'click': 
                dw_scrollObj.handleClick(links[i], wndoId, cls) ;
                break;
        }
    }
}

dw_scrollObj.handleMouseOverDownLinks = function (linkEl, wndoId, cls) {
    var parts = cls.split('_'); var eType = parts[0];
    var re = /^(mouseover|mousedown)_(up|down|left|right)(_[\d]+)?$/;
                
    if ( re.test(cls) ) { 
        var eAlt = (eType == 'mouseover')? 'mouseout': 'mouseup';
        var dir = parts[1];  var speed = parts[2] || null; 
        var deg = (dir == 'up')? 90: (dir == 'down')? 270: (dir == 'left')? 180: 0;
        
        dw_Event.add(linkEl, eType, function (e) { dw_scrollObj.col[wndoId].initScrollVals(deg, speed); } );
        dw_Event.add(linkEl, eAlt, function (e) { dw_scrollObj.col[wndoId].ceaseScroll(); } );
            
        if ( eType == 'mouseover') {
            dw_Event.add( linkEl, 'mousedown', function (e) { dw_scrollObj.col[wndoId].speed *= 3; } );
            dw_Event.add( linkEl, 'mouseup', function (e) { 
                dw_scrollObj.col[wndoId].speed = dw_scrollObj.prototype.speed; } ); 
        }
        dw_Event.add( linkEl, 'click', function(e) { if (e && e.preventDefault) e.preventDefault(); return false; } );
    }
}

dw_scrollObj.getEv_FnType = function(str) {
    var re = /^(mouseover|mousedown|scrollBy|scrollTo|scrollToId|click)$/;
    if (re.test(str) ) {
        return str;
    }
    return '';
}

dw_scrollObj.get_DelimitedClass = function(cls) {
    if ( cls.indexOf('_') == -1 ) {
        return '';
    }
    var whitespace = /\s+/;
    if ( !whitespace.test(cls) ) {
        return cls;
    } else {
        var classes = cls.split(whitespace); 
        for(var i = 0; classes[i]; i++) { 
            if ( classes[i].indexOf('_') != -1 ) {
                return classes[i];
            }
        }
    }
}

var dw_Event = {
  
    add: function(obj, etype, fp, cap) {
        cap = cap || false;
        if (obj.addEventListener) obj.addEventListener(etype, fp, cap);
        else if (obj.attachEvent) obj.attachEvent("on" + etype, fp);
    }, 

    remove: function(obj, etype, fp, cap) {
        cap = cap || false;
        if (obj.removeEventListener) obj.removeEventListener(etype, fp, cap);
        else if (obj.detachEvent) obj.detachEvent("on" + etype, fp);
    }, 
    
    DOMit: function(e) { 
        e = e? e: window.event; 
        if (!e.target) e.target = e.srcElement;
        if (!e.preventDefault) e.preventDefault = function () { e.returnValue = false; return false; }
        if (!e.stopPropagation) e.stopPropagation = function () { e.cancelBubble = true; }
        return e;
    },
    
    getTarget: function(e) {
        e = dw_Event.DOMit(e); var tgt = e.target; 
        if (tgt.nodeType != 1) tgt = tgt.parentNode; 
        return tgt;
    }
    
}