fixed bug: back button shows up when navigated to first modal in history

js/interface_common.js

@@ -397,20 +397,17 @@ function watchHashChange(e)
 {
 
     if(e!=null){ 
+
         var prevurlsplit = e.oldURL.split('#');
-        var newurlsplit = e.newURL.split('#');
         var prevhashstring=prevurlsplit[1];  
-        if(prevurlsplit[0]==newurlsplit[0] && prevhashstring!=undefined && prevhashstring.length>0 ){
-            $('.modal-back').css('display','inline');
-            //$('.modal-back').on('click', function(e){
-                //e.stopPropagation();
-                //e.preventDefault();
-                //window.location.hash = '#' + prevhashstring;
 
-                //window.history.go(-1);
+        var notFirstModalView=(prevhashstring!=undefined && prevhashstring.length>0 );
+        var notNavigatedBackToFirstModalView=(window.history.state==null || ( window.history.state!=null && window.history.state.showCloseButton!=false ) )
    
-            //});
+        if(notFirstModalView && notNavigatedBackToFirstModalView ) ){
+            $('.modal-back').css('display','inline');
         } else {
+            window.history.pushState({showCloseButton:false},null,null);
             $('.modal-back').css('display','none');
         }