Call to undefined function add_options_page()

Call to undefined function add_options_page()

I developed the plugin for my wordpress project. I successfully tested it
on my local xampp server with 5.3 php. Then I uploaded my project to the
web hosting with php 5.2. First trouble which with I faced off was
unsupporting anonymous functions in php 5.2. No issue, I redeclared all
functions with names. But then I got error Call to undefined function
add_options_page(), which I counldn't explain. Plz help me guys with your
advices
My part of code:
function mainPage(){
///some code
}
function mainPage2(){
add_options_page('Submissions of MAIN page contact form', 'Submissions
of MAIN page contact form', 'manage_options','ea_submissions2',
mainPage());
}
add_action('admin_menu',mainPage2());
I think something wrong with my funcitons, look through it please