void UpdateExtensions()
{
if (ExtensionList.GetNodeCount(true) > 0)
{
ExtensionList.Nodes.Clear();
}
foreach (Category Cat in CurrentCat)
{
TreeNode[] SubList = new TreeNode[Cat.Extensions.Count];
for (int i = 0; i < Cat.Extensions.Count; i++)
{
SubList[i] = new TreeNode(Cat.Extensions[i].Name);
}
ExtensionList.Nodes.Add(new TreeNode(Cat.Name, SubList));
}
}