Index: /trunk/src/org/openstreetmap/josm/data/coor/EastNorth.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/coor/EastNorth.java	(revision 4639)
+++ /trunk/src/org/openstreetmap/josm/data/coor/EastNorth.java	(revision 4640)
@@ -60,4 +60,13 @@
         return hd;
     }
+    
+    /**
+     * Replies true if east and north are different from Double.NaN
+     * 
+     * @return true if east and north are different from Double.NaN
+     */
+    public boolean isValid() {
+        return !java.lang.Double.isNaN(x) && !java.lang.Double.isNaN(y);
+    }
 
     public EastNorth sub(EastNorth en) {