diff --git a/web/app/fetchers.js b/web/app/fetchers.js
index 3564631f..caf59e0a 100644
--- a/web/app/fetchers.js
+++ b/web/app/fetchers.js
@@ -14,6 +14,22 @@ TCAD.TWO.ParametricManager.prototype._fetchTwoPoints = function(objs) {
   return points;
 };
 
+TCAD.TWO.ParametricManager.prototype._fetchPoints = function(objs) {
+  var points = [];
+  for (var i = 0; i < objs.length; ++i) {
+    objs[i].visit(false, function(o) {
+      if (o._class === 'TCAD.TWO.EndPoint')  {
+        points.push(o);
+      }
+      return true;
+    });
+  }
+  if (points.length == 0) {
+    throw "Illegal Argument. Constraint requires at least 1 point/line/arc."
+  }
+  return points;
+};
+
 TCAD.TWO.ParametricManager.prototype._fetchArcs = function(objs, min) {
   var arcs = [];
   for (var i = 0; i < objs.length; ++i) {
@@ -22,7 +38,7 @@ TCAD.TWO.ParametricManager.prototype._fetchArcs = function(objs, min) {
     }
   }
   if (arcs.length < min) {
-    throw "Illegal Argument. Constraint requires ata least " + min + " arcs."
+    throw "Illegal Argument. Constraint requires at least " + min + " arcs."
   }
   return arcs;
 };
diff --git a/web/app/main2d.js b/web/app/main2d.js
index 09959f67..537c13bd 100644
--- a/web/app/main2d.js
+++ b/web/app/main2d.js
@@ -105,6 +105,10 @@ TCAD.App2D = function() {
       app.viewer.parametricManager.tangent(app.viewer.selected);
     },
 
+    lock : function() {
+      app.viewer.parametricManager.lock(app.viewer.selected);
+    },
+
     analyze : function() {
       app.viewer.parametricManager.analyze(alert);
     }
@@ -124,6 +128,7 @@ TCAD.App2D = function() {
   actionsF.add(actions, 'Radius');
   actionsF.add(actions, 'R = R');
   actionsF.add(actions, 'tangent');
+  actionsF.add(actions, 'lock');
   actionsF.add(actions, 'analyze');
   actionsF.open();
 
diff --git a/web/app/parametric.js b/web/app/parametric.js
index be540e6b..2ee73fd7 100644
--- a/web/app/parametric.js
+++ b/web/app/parametric.js
@@ -12,6 +12,16 @@ TCAD.TWO.ParametricManager.prototype.add = function(constr) {
   this.viewer.refresh();
 };
 
+TCAD.TWO.ParametricManager.prototype.lock = function(objs) {
+  var p = this._fetchPoints(objs);
+  for (var i = 0; i < p.length; ++i) {
+    this.system.push(new TCAD.TWO.Constraints.EqualsTo(p[i]._x, p[i].x));
+    this.system.push(new TCAD.TWO.Constraints.EqualsTo(p[i]._y, p[i].y));
+  }
+  this.solve();
+  this.viewer.refresh();
+};
+
 TCAD.TWO.ParametricManager.prototype.vertical = function(objs) {
   var p = this._fetchTwoPoints(objs);
   this.add(new TCAD.TWO.Constraints.Equal(p[0]._x, p[1]._x));