diff --git a/mouseTrack.js b/mouseTrack.js
index c028b25..47ed508 100644
--- a/mouseTrack.js
+++ b/mouseTrack.js
@@ -192,7 +192,7 @@ document.onmouseup = function(event)
         else{
             --suppress
             // console.log('no move '+suppress)
-            $('#target').rmousedown(which=3);
+            if($('#target').rmousedown) $('#target').rmousedown(which=3);
         }
     }
 };