/**

 * @param contentDiv The id of a <div> containing the content that is to be scrolled

 * @param viewportDiv The id of a <div> within which the content should be displayed

 */

function ScrollingDiv(contentDiv, viewportDiv) {

	this.speed = 1;			// How many pixels it should move each time

	this.frequency = 60;	// How often (in ms) it should move 

	this.offset = 0;

	

	var that = this;

	this.pause = false;

	this.content = document.getElementById(contentDiv);

	this.viewport = document.getElementById(viewportDiv);

	this.content.onmouseover = function() {that.pause = true;};

	this.content.onmouseout = function() {that.pause = false;};

	this.viewport.style.overflow = 'hidden';

	

	this.scroll = function() {

		if (that.pause) {

			window.setTimeout(that.scroll, 500);

			return;

		}

		that.offset -= that.speed;

		if ((that.offset * -1) > that.content.scrollHeight)

			that.offset = 0;

		that.content.style.top = that.offset + 'px';

		window.setTimeout(that.scroll, that.frequency);

	}

	

	this.scroll();

}