function changeStyleSheet(type)
 {
 	switch (type) {
		case 'contrast_normal':
	    case 'contrast_contrast':
			$('#contrastStyleSheet').attr('href', '/public/css/display/' + type + '.css');
			break;
		case 'letter_normal':
		case 'letter_big':
		case 'letter_bigger':
			$('#letterStyleSheet').attr('href', '/public/css/display/' + type + '.css');
			break;
			
		default:
			$('#letterStyleSheet').attr('href', '/public/css/display/letter_normal.css');
			$('#contrastStyleSheet').attr('href', '/public/css/display/contrast_normal');
			
	}
	
 }