diff --git a/Scripts/Editor/NodeEditorGUILayout.cs b/Scripts/Editor/NodeEditorGUILayout.cs
index 1751d78..82f5fe2 100644
--- a/Scripts/Editor/NodeEditorGUILayout.cs
+++ b/Scripts/Editor/NodeEditorGUILayout.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Reflection;
+using System.Collections.Generic;
 using UnityEditor;
 using UnityEngine;
 
@@ -136,5 +137,29 @@ namespace XNodeEditor {
             GUI.DrawTexture(rect, NodeEditorResources.dot);
             GUI.color = col;
         }
+
+        /// <summary> Make a popup with all variable ids.</summary>
+        public static string VariablePopup(XNode.NodeGraph graph, string variableId, params GUILayoutOption[] options)
+        {
+            if (graph == null) return variableId;
+
+            List<string> variablesStrings = new List<string>();
+
+            foreach (var item in graph.variables)
+                variablesStrings.Add(item.id);
+              
+            int originalIdx = variablesStrings.IndexOf(variableId);
+            int newIdx = EditorGUILayout.Popup(originalIdx, variablesStrings.ToArray(), options);
+
+            if (originalIdx == -1 && newIdx == -1)
+            {
+                EditorGUILayout.HelpBox("Looks like the variable that used to be here, doesn't exist anymore. \n id:" + variableId, MessageType.Error);
+                return variableId;
+            }
+            
+            if (newIdx >= variablesStrings.Count)
+                return variableId;
+            return variablesStrings[newIdx];
+        }
     }
 }
\ No newline at end of file
diff --git a/Scripts/Editor/NodeGraphInspector.cs b/Scripts/Editor/NodeGraphInspector.cs
index 025d79b..32a5b24 100644
--- a/Scripts/Editor/NodeGraphInspector.cs
+++ b/Scripts/Editor/NodeGraphInspector.cs
@@ -13,13 +13,22 @@ namespace XNodeEditor
 	[CustomEditor(typeof(XNode.NodeGraph), true)]
 	public class NodeGraphInspector : Editor
 	{
-		SerializedProperty nodesProp;
 		SerializedProperty variablesProp;
 
+		List<Type> _knownTypes = new List<Type>();
 		void OnEnable()
 		{
-			nodesProp = serializedObject.FindProperty("nodes");
 			variablesProp = serializedObject.FindProperty("variables");
+			NodeGraph graph = target as NodeGraph;
+			
+			foreach (var node in graph.nodes)
+			{
+				foreach (var port in node.Ports)
+				{
+					if (!_knownTypes.Contains(port.ValueType))
+						_knownTypes.Add(port.ValueType);
+				}
+			}
 		}
 
 		public override void OnInspectorGUI()
@@ -74,20 +83,12 @@ namespace XNodeEditor
 			additionalTypes.Add(typeof(string).AssemblyQualifiedName);
 			additionalTypes.Add(typeof(Vector3).AssemblyQualifiedName);
 			
-			/*
-			Assembly asm = typeof(Vector3).Assembly;
-			foreach (var colorPair in NodeEditorPreferences.typeColors)
+			foreach (var type in _knownTypes)
 			{
-				var type = asm.GetType(colorPair.Key, false);
-				Debug.Log(colorPair.Key + "   " + type);
-
-				if (type == null)
-					continue;
 				if (additionalTypes.Contains(type.AssemblyQualifiedName))
 					continue;
-				additionalTypes.Add(colorPair.Key);
+				additionalTypes.Add(type.AssemblyQualifiedName);
 			}
-			*/
 
 			foreach (var addType in additionalTypes)
 			{