php codes

[dangerin]

Good morning,
i'm newly here.. Looking on the code of templates or every page i see that there are a lot of refer to some php functions how for example php_get_site_name or php_get_site_url etc etc
I'd want to understand where i found these functions and if is possible to change them
I need to put a logo where now there is a text on a template that i've installed and i hope that is possible but i found ths function on the code and to try to change and to verify if is ok i need to find firstly..
someone know where are or if there is in some place a research for the functions..
for example in vbulletin there is this function wneh i need to found a particular code and appear in every side is it.
Thanks to all

P.s. i know that VB and GS are different but i've only proposed an example in case someone do not understand what i said

BYE

[Connie]

I don't think you must enter any function

when you check the template / edit the template in the admin area, find where the text is defined and replace it whith the HTML of the image

if you would name the template which you are using, we could look deeper and tell you exactly what to change

[dangerin]

Thank you i found how to put the code replacing that is written.
i use two themes.. innovation and pixelstudioregular.
But what i ask is if there is a way to find that functions and to understand what they do or also modify them.
Thank newly