how do i test to see if a server is responding ?

hi, part of my website receives a data feed from another site. the problem is that if that site is down, the pages on my website don't display. what's the best way to if a site is up..... so far i have been using fopen - i've also tried using ping. any suggestions. thanks _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com