* Based on the global "highlight_from" and "highlight_to" variables.
*/
var update_board_highlight = function() {
* Based on the global "highlight_from" and "highlight_to" variables.
*/
var update_board_highlight = function() {
if ((current_display_line === null || current_display_line_is_history) &&
highlight_from !== undefined && highlight_to !== undefined) {
document.getElementById("board").querySelector('.square-' + highlight_from).classList.add('nonuglyhighlight');
if ((current_display_line === null || current_display_line_is_history) &&
highlight_from !== undefined && highlight_to !== undefined) {
document.getElementById("board").querySelector('.square-' + highlight_from).classList.add('nonuglyhighlight');