diff -r 96934a33d948 trunk/sites/all/modules/tagtool/tagtool.js
--- a/trunk/sites/all/modules/tagtool/tagtool.js	Sun Apr 11 09:59:14 2010 +0300
+++ b/trunk/sites/all/modules/tagtool/tagtool.js	Sun Apr 11 10:30:05 2010 +0300
@@ -37,14 +37,17 @@ if (Drupal.jsEnabled) {
           .addClass('tag-item')
           .mouseover(function () { $(this).addClass('hover');})
           .mouseout(function () { $(this).removeClass('hover'); });
         $(this.popup).append(div);
       }
       $(this.popup).fadeIn('fast');
       $('.tag-item').click(function () {
         var now_value = $(auto_input).val();
+        var trimmed = $.trim(now_value);
+        if (trimmed.length > 0 && trimmed.lastIndexOf(",") != trimmed.length - 1) 
+            now_value += ', ';
         $(auto_input).val(now_value + $(this).html() + ', ');
       });
     });
   });
 }