diff --git a/web/app/canvas.js b/web/app/canvas.js
index a4278d8b..13295eda 100644
--- a/web/app/canvas.js
+++ b/web/app/canvas.js
@@ -647,6 +647,7 @@ TCAD.TWO.DragTool = function(obj, viewer) {
   this.ref = this.obj.getReferencePoint();
   this.errorX = 0;
   this.errorY = 0;
+  this.solver = null;
 };
 
 TCAD.TWO.DragTool.prototype.keydown = function(e) {};
@@ -678,6 +679,7 @@ TCAD.TWO.DragTool.prototype.mousemove = function(e) {
 
 TCAD.TWO.DragTool.prototype.mousedown = function(e) {
   this.viewer.screenToModel2(e.x, e.y, this._point);
+  this.prepareSolver();
 };
 
 TCAD.TWO.DragTool.prototype.mouseup = function(e) {
@@ -690,6 +692,11 @@ TCAD.TWO.DragTool.prototype.mousewheel = function(e) {
 };
 
 TCAD.TWO.DragTool.prototype.solveRequest = function(fineLevel) {
+  this.solver.solve(fineLevel);
+};
+
+TCAD.TWO.DragTool.prototype.prepareSolver = function() {
+
   var locked;
   if (this.obj._class === 'TCAD.TWO.EndPoint') {
     locked = [this.obj._x, this.obj._y];
@@ -704,5 +711,5 @@ TCAD.TWO.DragTool.prototype.solveRequest = function(fineLevel) {
   } else {
     locked = [];
   }
-  this.viewer.parametricManager.solve(locked, fineLevel);
+  this.solver = this.viewer.parametricManager.prepare(locked); 
 };
diff --git a/web/app/constr/solver.js b/web/app/constr/solver.js
index b39204e8..8d869dfe 100644
--- a/web/app/constr/solver.js
+++ b/web/app/constr/solver.js
@@ -197,10 +197,12 @@ TCAD.parametric.lock1 = function(constrs, locked) {
   }
 };
 
-TCAD.parametric.lock2 = function(constrs, locked) {
+TCAD.parametric.lock2Equals2 = function(constrs, locked) {
+  var _locked = [];
   for (var i = 0; i < locked.length; ++i) {
-    constrs.push(new TCAD.constraints.EqualsTo([locked[i]], locked[i].get()));
+    _locked.push(new TCAD.constraints.EqualsTo([locked[i]], locked[i].get()));
   }
+  return _locked;
 };
 
 TCAD.parametric.prepare = function(constrs, locked, alg) {
@@ -209,8 +211,9 @@ TCAD.parametric.prepare = function(constrs, locked, alg) {
 
 
 //  this.lock1(constrs, locked);
-  this.lock2(constrs, locked);
-
+  var lockingConstrs = this.lock2Equals2(constrs, locked);
+  Array.prototype.push.apply( constrs, lockingConstrs );
+  
   var sys = new TCAD.parametric.System(constrs);
 
   if (sys.params.length == 0) return;
@@ -281,7 +284,12 @@ TCAD.parametric.prepare = function(constrs, locked, alg) {
   }
   var systemSolver = {
     system : sys,
-    solveSystem : solve 
+    solveSystem : solve,
+    updateLock : function(values) {
+      for (var i = 0; i < values.length; ++i) {
+        lockingConstrs[i].value = values[i];
+      }
+    }
   };
   
   return systemSolver;
diff --git a/web/app/parametric.js b/web/app/parametric.js
index 16c1eabb..70112c0b 100644
--- a/web/app/parametric.js
+++ b/web/app/parametric.js
@@ -276,9 +276,16 @@ TCAD.TWO.ParametricManager.prototype.prepare = function(locked, alg) {
       lockedIds[locked[p]] = true;
     }
   }
-
+  
+  var lockedValues = [];
   var solver = TCAD.parametric.prepare(_constrs, _locked, alg);
   function solve(fineLevel) {
+    if (_locked.length != 0) {
+      for (p = 0; p < locked.length; ++p) {
+        lockedValues[p] = locked[p].get() ;
+      }
+      solver.updateLock(lockedValues);
+    }
     solver.solveSystem(fineLevel);
     for (p in pdict) {
       _p = pdict[p];