diff --git a/index.html b/index.html
index 8986b61..4f3e5bc 100755
--- a/index.html
+++ b/index.html
@@ -196,10 +196,11 @@ var Pivot =
         //    - optional traversal depth, defaults to 0
         let depth = inDepth||0;
         let uniques = {};
+        let indexPivot = inPivotIndicies[depth]
         inParent.Meta.Leaves.forEach((inLeaf)=>
         {
             let row = inLeaf.Meta.Row; // shorthand for the raw "CSV" row in the leaf Node's Meta
-            let value = row[inPivotIndicies[depth]]; // get the pivot column
+            let value = row[indexPivot]; // get the pivot column
             let match = uniques[value]; // check in the uniques list if this pivot column exists
             if(!match)
             {
@@ -213,6 +214,8 @@ var Pivot =
                 match = uniques[value] = {
                     Label:value,
                     Row:clone, 
+                    IndexPivot:indexPivot,
+                    IndexSum:inSumIndicies,
                     Leaves:[]
                 };
                 // grow a child off of the parent using the meta object
@@ -370,8 +373,8 @@ import { useReducer } from 'https://cdn.skypack.dev/preact/hooks';
 import { css, cx } from 'https://cdn.skypack.dev/@emotion/css';
 
 Pivot.Init(
-    ["number", "type-a", "type-b", "count"],
-    ["label", "label", "label", "sum"],
+    ["number", "type-a", "type-b", "count", "extra"],
+    ["label", "label", "label", "sum", "sum"],
     [
     ["#1", "a", "long",  1, 4],
     ["#2", "b", "long",  2, 4],
@@ -385,21 +388,24 @@ Pivot.Init(
 
 let ElForm = props =>
 {
-    let labelColumns = N.Step(Pivot.Schema, "label")||[];
+    let pivotColumns = N.Step(Pivot.Schema, "label")||[];
+    let pivotColumnsUsed = N.Step(Pivot.Proto, "used-pivot")||[];
 
-    let used = N.Step(Pivot.Proto, "used")||[];
-    let unused = N.Step(Pivot.Schema, "label").filter( columnLabel => !N.Step(columnLabel, "used", false) );
-    let indiciesPivot = used.map(node=>node.Meta.Index);
-    let indiciesSum = (N.Step(Pivot.Schema, "sum")||[]).map(n=>n.Meta.Index);
+    let sumColumns = N.Step(Pivot.Schema, "sum")||[];
+    let sumColumnsUsed = N.Step(Pivot.Proto, "used-sum")||[];
+
+    let indiciesPivot = pivotColumnsUsed.map(node=>node.Meta.Index);
+    let indiciesSum = sumColumnsUsed.map(node=>node.Meta.Index);
     
     var action;
     if(indiciesPivot.length)
     {
-        action = h("div", null, [
+        action = h("p", null, [
             h("span", null, "Build"),
             h("button", {onClick:e=>
             {
-                N.Disconnect(Pivot.Proto, null, "used");
+                N.Disconnect(Pivot.Proto, null, "used-pivot");
+                N.Disconnect(Pivot.Proto, null, "used-sum");
                 Pivot.Create(indiciesPivot, indiciesSum);
                 Render();
             }
@@ -408,35 +414,71 @@ let ElForm = props =>
     }
     else
     {
-        action = h("div", null, "(select columns)")
+        action = h("p", null, "(select columns)")
     }
 
     return h("div", {}, [
-        h("div", null, [
-            h("span", null, "available"),
-            ...unused.map( node=>
+        h("p", null, [
+
+            h("span", null, "Pivot Columns"),
+            ...pivotColumns.map( columnLabel =>
             {
-                return h("button", {onClick:e=>
+                let attributes = {};
+                if(N.Step(columnLabel, "used-pivot", false))
                 {
-                    N.Connect(Pivot.Proto, node, "used");
-                    Render();
+                    attributes.disabled = true;
                 }
-                }, node.Meta.Label);
-            }
-            )
+                else
+                {
+                    attributes.onClick = e=>
+                    {
+                        N.Connect(Pivot.Proto, columnLabel, "used-pivot");
+                        Render();
+                    }
+                }
+                return h("button", attributes, columnLabel.Meta.Label);
+            }),
+
+            h("span", null, "Summation Columns"),
+            ...sumColumns.map( columnSum =>
+            {
+                let attributes = {};
+                if(N.Step(columnSum, "used-sum", false))
+                {
+                    attributes.disabled = true;
+                }
+                else
+                {
+                    attributes.onClick = e=>
+                    {
+                        N.Connect(Pivot.Proto, columnSum, "used-sum");
+                        Render();
+                    }
+                }
+                return h("button", attributes, columnSum.Meta.Label);
+            })
         ]),
-        h("div", null, [
-            h("span", null, "taken"),
-            ...used.map( node=>
+        h("p", null, [
+            h("span", null, "Current Pivot"),
+            ...pivotColumnsUsed.map( columnLabel =>
             {
                 return h("button", {onClick:e=>
                 {
-                    N.Disconnect(Pivot.Proto, node, "used");
+                    N.Disconnect(Pivot.Proto, columnLabel, "used-pivot");
                     Render();
                 }
-                }, node.Meta.Label);
-            }
-            )
+                }, columnLabel.Meta.Label);
+            }),
+            h("span", null, "Current Summation"),
+            ...sumColumnsUsed.map( columnSum =>
+            {
+                return h("button", {onClick:e=>
+                {
+                    N.Disconnect(Pivot.Proto, columnSum, "used-sum");
+                    Render();
+                }
+                }, columnSum.Meta.Label);
+            }),
         ]),
         action
     ])