fixed len being undeclared

src/fx.js

@@ -584,7 +584,7 @@ SVG.FX = SVG.invent({
 
     // calculates the step for every property and calls block with it
   , eachAt: function(){
-      var i, at, self = this, target = this.target(), s = this.situation
+      var i, len, at, self = this, target = this.target(), s = this.situation
 
       // apply animations which can be called trough a method
       for(i in s.animations){