php calling mail and failing

i am trying to set up a home page with an email form, where i can fill out email address and subject and comments and the php page will run

mail -s my@email.com $comments how can I do this via php to call the linux 开发者_如何学JAVAcommand?

thanks in advance

mail("youremail@domain.com","Subject","The message content");

http://us3.php.net/manual/en/function.mail.php

Why don't you just use PHP's own mail() function?