Include php file to header

Hi,

I am trying to add some php code, given to me by google analytics, to the header of my website.
I can't figure out how to include php files to all my pages.

Thannks for any help.

Hi,
Which theme exactly are you using?

Instyle theme.
I acutally made it by using include_once("MyFile.php");
But i don't know if it's the best practice.

Generally you should use get_template_part within theme files, but include_once will also work properly.
Please check i.e. this article: http://code.tutsplus.com/articles/how-t ... --wp-26419