private void add_list_Click(object sender, EventArgs e)
{
string xmlFile = txt_list1.Text;
ExtensionCollection list = new ExtensionCollection();
ExtensionCollection list2 = new ExtensionCollection();
if (File.Exists(xmlFile))
list = ExtensionCollection.Load(xmlFile);
if (File.Exists(txt_list2.Text))
list2 = ExtensionCollection.Load(txt_list2.Text);
list.Add(list2);
list.Save(xmlFile);
}
