fixed locktimer/draft saving on new pages

When creating new pages, no date field is added in the edit form.

lib/exe/ajax.php

@@ -139,7 +139,7 @@ function ajax_lock(){
                    'prefix' => $_POST['prefix'],
                    'text'   => $_POST['wikitext'],
                    'suffix' => $_POST['suffix'],
-                   'date'   => $_POST['date'],
+                   'date'   => (int) $_POST['date'],
                    'client' => $client,
                   );
     $cname = getCacheName($draft['client'].$id,'.draft');

lib/scripts/edit.js

@@ -418,7 +418,9 @@ var locktimer = new locktimer_class();
                 params += '&prefix='+encodeURIComponent(dwform.elements.prefix.value);
                 params += '&wikitext='+encodeURIComponent(dwform.elements.wikitext.value);
                 params += '&suffix='+encodeURIComponent(dwform.elements.suffix.value);
-                params += '&date='+encodeURIComponent(dwform.elements.date.value);
+                if(dwform.elements.date){
+                    params += '&date='+encodeURIComponent(dwform.elements.date.value);
+                }
             }
             locktimer.sack.runAJAX(params);
             locktimer.lasttime = now;