This simple code will give you an array containing all files in a directory.
<%@ Page Language="C#" %>
<%@ Import Namespace="System.IO" %>
<script runat="server">
void Page_Load(object sender, EventArgs e) {
FileInfo fi = new FileInfo(Server.MapPath(""));
DirectoryInfo di = fi.Directory;
FileSystemInfo[] fsi = di.GetFiles();
Response.Write("The directory contains the following files and directories:" + di.FullName + "<hr>");
foreach (FileSystemInfo info in fsi)
Response.Write(info.Name + "<br>");
}
</script>