do not call correctPNG() when undefined

diff --git a/prefs.js b/prefs.js
index ab8953bd402edf7711bd4e8e319e696b899e6e83..60a7e1b17e08f401a318016cb36d23a46f5fe2e9 100644 (file)
--- a/prefs.js
+++ b/prefs.js
@@ -42,7 +42,9 @@ function feedlist_callback() {
 
                                caller_subop = false;
                        }
-                       correctPNG();
+                       if (typeof correctPNG != 'undefined') {
+                               correctPNG();
+                       }
                        notify("");
                } catch (e) {
                        exception_error("feedlist_callback", e);
@@ -54,7 +56,9 @@ function filterlist_callback() {
        var container = document.getElementById('prefContent');
        if (xmlhttp.readyState == 4) {
                container.innerHTML=xmlhttp.responseText;
-               correctPNG();
+               if (typeof correctPNG != 'undefined') {
+                       correctPNG();
+               }
                notify("");
        }
 }
@@ -77,7 +81,9 @@ function labellist_callback() {
                                checkbox.checked = true;
                        }
                }
-               correctPNG();
+               if (typeof correctPNG != 'undefined') {
+                       correctPNG();
+               }
                notify("");
        }
 }