Securety exception on browse

[DllImport("msvcrt.dll", SetLastError=true)]
private static extern int _mkdir(string path) ;

ArrayList oDirsToCreate = new ArrayList() ;

         // Create the directory info object for that dir (normalized to its absolute representation).
         DirectoryInfo oDir = new DirectoryInfo( Path.GetFullPath( path ) ) ;

         // Check the entire path structure to find directories that must be created.
         while ( oDir != null && !oDir.Exists )
         {
            oDirsToCreate.Add( oDir.FullName ) ;
            oDir = oDir.Parent ;
         }

         // "oDir == null" means that the check arrives in the root and it doesn't exist too.
         if ( oDir == null )
            throw( new System.IO.DirectoryNotFoundException( "Directory \"" + oDirsToCreate[ oDirsToCreate.Count-1 ] + "\" not found." ) ) ;

         // Create all directories that must be created (from bottom to top).
         for( int i = oDirsToCreate.Count - 1 ; i >= 0 ; i-- )
         {
            string sPath = (string)oDirsToCreate[i] ;
            int iReturn = _mkdir( sPath ) ;

            if ( iReturn != 0 )
               throw new ApplicationException("Error calling [msvcrt.dll]:_wmkdir(" + sPath + "), error code: " + iReturn );
         }

System.IO.Directory.CreateDirectory(path);

/*
 * FCKeditor - The text editor for internet
 * Copyright (C) 2003-2005 Frederico Caldeira Knabben
 * 
 * Licensed under the terms of the GNU Lesser General Public License:
 *       http://www.opensource.org/licenses/lgpl-license.php
 * 
 * For further information visit:
 *       http://www.fckeditor.net/
 * 
 * "Support Open Source software. What about a donation today?"
 * 
 * File Name: Util.cs
 *    Useful tools.
 * 
 * File Authors:
 *       Frederico Caldeira Knabben (fredck@fckeditor.net)
 */

using System ;
using System.Runtime.InteropServices ;
using System.IO ;
using System.Collections ;

namespace FredCK.FCKeditorV2
{
   public sealed class Util
   {
      private Util()
      {}

      public static DirectoryInfo CreateDirectory( string path )
      {
         System.IO.Directory.CreateDirectory(path);
         return new DirectoryInfo( path ) ;
      }
   }
}