+function parse_image_num(url, default_value) {
+ var url_array = (window.location.toString().split("#"));
+ if (url_array.length != 2) {
+ return default_value;
+ }
+
+ var num = parseInt(url_array[1]);
+ if (num > 1 && num <= global_image_list.length) { // and then num != NaN
+ return (num - 1);
+ } else {
+ return default_value;
+ }
+}
+