The following code works well for me. On the old-site.com, create a blank index.html or default.html and paste in the following code, save it and you are done.
<meta http-equiv="Content-Language" content="en-us"><META HTTP-EQUIV="REFRESH" CONTENT="0; URL=http://new-site.com">
Alter CONTENT="0" to the number of seconds you like to wait before the redirect takes place. Use "0; to forward immediately.
Hope this helps. Peace!