var photo_layer=0;$(document).ready(function(){$("#prev_photos").click(function(){$("#photo_ul"+photo_layer).hide();photo_layer=photo_layer+1;if(photo_layer>3)photo_layer=0;$("#photo_ul"+photo_layer).show();});$("#next_photos").click(function(){$("#photo_ul"+photo_layer).hide();photo_layer=photo_layer-1;if(photo_layer<0)photo_layer=3;$("#photo_ul"+photo_layer).show();});});