diff -r 7cadc624cc74 -r 996515c4b394 controls/VariablePanel.py
--- a/controls/VariablePanel.py	Wed Sep 05 12:38:41 2012 +0200
+++ b/controls/VariablePanel.py	Wed Sep 05 12:39:50 2012 +0200
@@ -232,6 +232,7 @@
         self.ParentWindow = parent
     
     def OnDropText(self, x, y, data):
+        self.ParentWindow.ParentWindow.Select()
         x, y = self.ParentWindow.VariablesGrid.CalcUnscrolledPosition(x, y)
         col = self.ParentWindow.VariablesGrid.XToCol(x)
         row = self.ParentWindow.VariablesGrid.YToRow(y - self.ParentWindow.VariablesGrid.GetColLabelSize())
@@ -272,22 +273,26 @@
                             elif base_type not in LOCATIONDATATYPES[location[0]]:
                                 message = _("Incompatible size of data between \"%s\" and \"%s\"")%(location, variable_type)
                             else:
-                                dialog = wx.SingleChoiceDialog(self.ParentWindow, 
+                                dialog = wx.SingleChoiceDialog(self.ParentWindow.ParentWindow.ParentWindow, 
                                       _("Select a variable class:"), _("Variable class"), 
                                       ["Input", "Output", "Memory"], 
                                       wx.DEFAULT_DIALOG_STYLE|wx.OK|wx.CANCEL)
                                 if dialog.ShowModal() == wx.ID_OK:
                                     selected = dialog.GetSelection()
-                                    if selected == 0:
-                                        location = "%I" + location
-                                    elif selected == 1:
-                                        location = "%Q" + location
-                                    else:
-                                        location = "%M" + location
-                                    self.ParentWindow.Table.SetValue(row, col, location)
-                                    self.ParentWindow.Table.ResetView(self.ParentWindow.VariablesGrid)
-                                    self.ParentWindow.SaveValues()
+                                else:
+                                    selected = None
                                 dialog.Destroy()
+                                if selected is None:
+                                    return
+                                if selected == 0:
+                                    location = "%I" + location
+                                elif selected == 1:
+                                    location = "%Q" + location
+                                else:
+                                    location = "%M" + location
+                                self.ParentWindow.Table.SetValue(row, col, location)
+                                self.ParentWindow.Table.ResetView(self.ParentWindow.VariablesGrid)
+                                self.ParentWindow.SaveValues()
                 elif colname == "Initial Value" and values[1] == "Constant":
                     if not self.ParentWindow.Table.GetValueByName(row, "Edit"):
                         message = _("Can't set an initial value to a function block instance")