script in PHP to check whether the server is alive or not

I am internee at software testing and given the task to write a script in PHP which will be placed on the server and it will check after every 10 mins that whether the server is alive or not. i have looked up and found different solutions. " http://snipplr.com/view/33950 ", "http://www.thecave.info/php-ping-script-to-check-remote-server-or-website/" these two are quite understandable as i'm a new-bee, but when i tried to copy and run the same task then both are not working for me! the first link is not giving any output while the second one is always giving the "server is down" message. I've tried playing around with different articles to do this but have come away with nothing so far! if the solutions are provided with elaborated examples it would be highly appreciable. Thanks in anticipation :)