[Plugin: NextGEN Gallery] Add left right keyboard navigation to thickbox

I do realize that this thread is more than 6 months old but this particular issue was bothering me for a while, looked for a solution online and couldn’t find one. So I spent some time trying to work it out and I did. I decided to post it here since I’m probably far not the only one who is trying to figure it out. It’s as simple as it could get. go to
/wp-includes/js/

open thickbox.js and look for e.which and you will find the following:

if ( e.which == 27 ){ // close
					if ( ! jQuery(document).triggerHandler( 'wp_CloseOnEscape', [{ event: e, what: 'thickbox', cb: tb_remove }] ) )
						tb_remove();

				} else if ( e.which == 190 ){ // display previous image 190(<)
					if(!(TB_NextHTML == "")){
						jQuery(document).unbind('thickbox');
						goNext();
					}
				} else if ( e.which == 188 ){ // display next image 188 (>)
					if(!(TB_PrevHTML == "")){
						jQuery(document).unbind('thickbox');
						goPrev();
					}
				}

once you find that-replace 190 with 39 and 188 with 37. save and you are done