Fix interactive variables declaration order.

src/jquery.flot.js

@@ -814,6 +814,10 @@ Licensed under the MIT license.
                 hooks: {}
             },
 
+            // interactive features
+            highlights = [],
+            redrawTimeout = null,
+
             // the canvas for the plot itself
             surface = null,
 
@@ -3378,10 +3382,6 @@ Licensed under the MIT license.
             }
         }
 
-        // interactive features
-        var highlights = [],
-            redrawTimeout = null;
-
         /**
          * returns the data item the mouse is over, or null if none is found
          */