Okay, I'm learning PHP using some eBook, I have some newbie question here. How to use a variable without getting the "undefined variable" notice from the compiler? For example, I have this line:

$movie_list=array_merge($movie_list, $movie);

This is the first line where this variable is used. I want $movie_list to be an empty array, so I can append my $movie array to it each time the "foreach" loop goes in order form a movie list.
Am I suppose to declare an empty array such that $movie_list is not undefined when the compiler see it? How to declare an empty array?
Another newbie question, when you use print function such as below:

print "<SPAN class='headline'>My title</SPAN>";

I am forced to use ' instead of " for my headline css class, or else the compiler will give me error. Can I use "headline" instead of 'headline' without getting an error?
I hope my question make sense. I'm using PHP 4.3, testing on Abyss Web Server. Ah, also where is the php.ini file, and how do I use it? Thank you very much!