function Scroll(id, speed) {
        this.speed = speed;
        this.oDiv = document.getElementById(id);
        this.content = this.oDiv.innerHTML;
        this.scroll_layer = "<div id='scroller_" + id + "' style='position: relative;'>" + this.content + "</div>";
        this.oDiv.innerHTML = this.scroll_layer;
        this.oScroll = document.getElementById('scroller_' + id);
        this.start();
}

Scroll.prototype.paused = false;

Scroll.prototype.oDiv = new Object();
Scroll.prototype.oScroll = new Object();

Scroll.prototype.content = "";
Scroll.prototype.scroll_layer = "";
Scroll.prototype.mask_height = 0;

Scroll.prototype.speed = 1;

Scroll.prototype.start = function() {
        this.paused = false;
        this.mask_height = this.oDiv.offsetHeight;
        
        this.oScroll.style.position = 'relative';
        this.oScroll.style.top = this.mask_height + "px";
        this.oScroll.style.left = 0;
        
        this.scroll();
};

Scroll.prototype.pause = function() {
        this.paused = true;
};

Scroll.prototype.resume = function() {
        this.paused = false;
};

Scroll.prototype.scroll = function() {
        if (!this.paused) {
                this.oScroll.style.top = (parseInt(this.oScroll.style.top) - this.speed) + "px";
                if (parseInt(this.oScroll.offsetTop) <= this.oDiv.offsetTop - this.oScroll.offsetHeight) {
                        this.oScroll.style.top = this.mask_height + "px";
                }
        }
        
        var _self = this;
        window.setTimeout(function() {
                        _self.scroll();
                        }, 50);
};

Scroll.prototype.showContent = function() {
        alert(this.content);
};