private void btnAddVariable_Click(object sender, EventArgs e)
        {
            var            env = (EnvironmentSet)cbVariableSet.SelectedItem;
            VariableEditor ve  = new VariableEditor("", "");

            if (ve.ShowDialog() == DialogResult.OK)
            {
                env.Variables[ve.VariableName] = ve.DefaultValue;
                updated = true;
                RefreshLbVariables();
            }
        }
        private void lbVariables_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            var            env     = (EnvironmentSet)cbVariableSet.SelectedItem;
            string         varName = (string)lbVariables.SelectedItem;
            VariableEditor ve      = new VariableEditor(varName, (string)env.Variables[varName]);

            if (ve.ShowDialog() == DialogResult.OK)
            {
                env.Variables.Remove(varName);
                env.Variables[ve.VariableName] = ve.DefaultValue;
                updated = true;
                RefreshLbVariables();
            }
        }