var scroll_buffer = '';
var scroller_length = 104;
var stop_scroller = false;

function toggle_scroller() {
	if (stop_scroller) {
		// restart the text scroller
		stop_scroller = false;
		scroll();
	}
	else {
		stop_scroller = true;
	}
}

function scroll() {

	// let the user stop and start the text scrolling
	if (stop_scroller) {return;}
	
	// duplicate short scroll text to fill
	if (scroll_text.length < 100) {
		scroll_buffer = '';
		while ( scroll_buffer.length < 100 ) {
			scroll_buffer = scroll_buffer + scroll_text + '      ';
		}
	}
	else {
		scroll_buffer = scroll_text;
	}
	
	// select sub-section of text to display
	display_text = scroll_buffer.substring(scroll_offset, scroll_offset+scroller_length);

	// wrap the text
	if (display_text.length < scroller_length) {
		wrapped_text = scroll_buffer.substring(0,scroller_length - display_text.length);
		display_text = display_text + wrapped_text;
	}
	
	// display the text
	display_text = display_text.replace(/ /g, '&nbsp;')
	document.getElementById('scroller').innerHTML = display_text;

	// shift the text 'scroll' it.
	scroll_offset += 1;
	if (scroll_offset > scroll_buffer.length) { scroll_offset = 0 }

	setTimeout(scroll, 200);
}