prevent syntax error when invalid hash is given

ktsaou · ktsaou · commit 8865b8f05e29 · 2016-10-06T20:42:26.000+03:00
diff --git a/web/index.html b/web/index.html
@@ -915,7 +915,7 @@
     // scroll to a section, without changing the browser history
 
     function scrollToId(hash) {
-        if(hash && hash != '') {
+        if(hash && hash != '' && document.getElementById(hash) !== null) {
             var offset = $('#' + hash).offset();
             if(typeof offset !== 'undefined')
                 $('html, body').animate({ scrollTop: offset.top }, 0);
