diff --git a/src/test.coffee b/src/test.coffee
index 5eadbf8..4ff216c 100644
--- a/src/test.coffee
+++ b/src/test.coffee
@@ -8,7 +8,7 @@ z=new Vector2(v)
 console.log(z)
 
 
-###test add
+#test add
 v.add(1)
 console.log v.getX(),v.getY()
 v.add(v)
@@ -21,4 +21,4 @@ console.log v.getX(),v.getY()
 
 n = new WorldObject()
 console.log(n)
-###
\ No newline at end of file
+
diff --git a/src/vector.coffee b/src/vector.coffee
index 988529a..7baafe8 100644
--- a/src/vector.coffee
+++ b/src/vector.coffee
@@ -1,7 +1,7 @@
 class Vector2
   constructor:(@x=0,@y=0) ->
-    if @x instanceof Vector2
-      vec=@x
+    if x instanceof Vector2
+      vec=x
       @x=vec.x
       @y=vec.y
   
@@ -88,7 +88,7 @@ class Vector3
     return this.z
   # add ascalar
   add: (vec) ->
-    if typeof vec is "Vector2"
+    if vec instanceof Vector3
       this.x += vec.getX()
       this.y += vec.getY()
     else