void SaveExtensions()
{
// Save it
if (Properties.Settings.Default.ExtensionSets != null) Properties.Settings.Default.ExtensionSets.Clear();
StringCollection strExtSet = new StringCollection();
foreach (String strExt in txtExt.Items)
{
strExtSet.Add(strExt);
}
Properties.Settings.Default.ExtensionSets = strExtSet;
Properties.Settings.Default.Save();
}