diff --git a/controller.js b/controller.js
index 15af324..24ec70c 100644
--- a/controller.js
+++ b/controller.js
@@ -17,6 +17,12 @@ var NumberController = function() {
     this.inc = 0;   // TODO pass argument to inc
     this.button;
     
+    console.log(arguments);
+    
+    // Get min and max
+    (arguments[2] != null) ? this.min = arguments[2] : this.min = null;
+    (arguments[3] != null) ? this.max = arguments[3] : this.max = null;
+    
     this.button = document.createElement('input');
     this.button.setAttribute('id', this.propertyName);
     this.button.setAttribute('type', 'number');
@@ -37,12 +43,27 @@ var NumberController = function() {
             _this.y = e.offsetY;
             var dy = _this.y - _this.py;
             
-            if(dy > 0)
-                _this.button.setAttribute('value', _this.inc++);
-            else if(dy < 0)
-                _this.button.setAttribute('value', _this.inc--);
+            if(dy > 0) {
+                if(_this.max != null)
+                    (_this.inc >= _this.max) ? _this.inc = _this.max : _this.inc++;
+                else
+                    _this.inc++;
+            } else if(dy < 0) {
+                
+                if(_this.min != null)
+                    (_this.inc <= _this.min) ? _this.inc = _this.min : _this.inc--;
+                else
+                    _this.inc--;
+            }
+            
+            _this.button.setAttribute('value', _this.inc);
         }
     };
+    
+    this.__defineSetter__("position", function(val) {
+        _this.inc = val;
+        _this.button.setAttribute('value', _this.inc);
+    });
 };
 
 NumberController.prototype = new Controller();
diff --git a/demo.html b/demo.html
index 2cb5afb..b7490fc 100644
--- a/demo.html
+++ b/demo.html
@@ -24,7 +24,7 @@ window.onload = function() {
 	GUI.add(controllableObject, "numberProperty");
 	
 	// Creates a slider (min, max)
-	GUI.add(controllableObject, "anotherNumberProperty", -100, 100);
+    GUI.add(controllableObject, "anotherNumberProperty", -100, 100);
 	
 	// Creates a text field
 	GUI.add(controllableObject, "textProperty");
diff --git a/gui.js b/gui.js
index 8bd0cb5..add48df 100644
--- a/gui.js
+++ b/gui.js
@@ -57,8 +57,7 @@ var GUI = new function() {
 	var addHandlers = {
 		
 		"number": function() {
-            var n = new NumberController(arguments);
-            return n;
+            return construct(NumberController, arguments);
 		},
 		
 		"string": function() {
@@ -85,6 +84,14 @@ var GUI = new function() {
 			console.error("[GUI ERROR] " + str);
 		}
 	};
+	
+	var construct = function(constructor, args) {
+        function F() {
+            return constructor.apply(this, args);
+        }
+        F.prototype = constructor.prototype;
+        return new F();
+    };
 
 
 
@@ -143,4 +150,4 @@ var GUI = new function() {
 		
 	};
 	
-};
+};
\ No newline at end of file