is there a tool available for checking for errors in a php file/page

You can get this functionality from a decent IDE like eclipse or Zend.

Failing that you can output error messages (line numbers etc) by inserting this line to the start of your php.
error_reporting(E_ALL);

Then any warnings error etc will be given on the page your running the script on.

Ibbo

Apache error logs list it if the page itself doesnt. Also running the file through php.exe is default verbose.

Also see helpful notes from php.net on error handling:
http://us3.php.net/manual/en/function.error-log.php

Be careful if you use email notifications for error reporting...

-J