DirectoryInfo dirinfo = new DirectoryInfo(Server.MapPath("upload"));
FileSystemInfo[] dirs = dirinfo.GetFileSystemInfos();
if (dirs.Length > 1)
{
DropDownList1.DataSource = dirs;
DropDownList1.DataBind();
}
FileSystemInfo[] dirs = dirinfo.GetFileSystemInfos();
if (dirs.Length > 1)
{
DropDownList1.DataSource = dirs;
DropDownList1.DataBind();
}