correcting coordinate calculations

examples/mouse.rkt

@@ -10,8 +10,10 @@
 
 (define (mouse world x y type)
   (cond
-   [(string=? type "click")
+   
+   [(string=? type "move")
     (make-posn x y)]
+
    [else
     world]))
 
@@ -21,7 +23,7 @@
                (posn-y w)
                (empty-scene width height)))
                        
-
+(printf "let's see how this works.\n\n")
 (big-bang (make-posn 0 0)
           (on-mouse mouse)
           (to-draw draw))

world/raw-jsworld.js

@@ -926,8 +926,11 @@ var rawJsworld = {};
 	    var makeWrapped = function(type) {
                 return function(e) {
                     var x = e.pageX, y = e.pageY;
-                    x -= e.target.offsetLeft;
-                    y -= e.target.offsetLeft;
+                    var currentElement = e.target;
+                    do {
+                        x -= currentElement.offsetLeft;
+                        y -= currentElement.offsetTop;
+                    } while(currentElement = currentElement.offsetParent);
 		    preventDefault(e);
 		    stopPropagation(e);
 		    change_world(function(w, k) {