private void AddActionArgument() { string error; try { ActionArgument actionArg = new ActionArgument(); actionArg.Name = txtName.Text; actionArg.Expression = BuildExpression(); if (actionArg.IsValid()) { actionArgs.Add(actionArg); RefreshActionArguments(); txtName.Text = string.Empty; cbTarget.Text = string.Empty; cbPropertyOrValue.Text = string.Empty; ckIgnoreErrors.Checked = false; return; } else { error = actionArg.Error; } } catch(Exception e) { error = e.Message; } MessageBox.Show(error, "Add Action Argument", MessageBoxButtons.OK, MessageBoxIcon.Error); }