[PHP] What if conditional methode to do this? please help

i have responsive template, its have 3 php files :

– templatedesktop.php : template file for desktop

– templatemobile.php : template file for mobile

– page.php : contain information content, its included templatedesktop.php & templatemobile.php file inside

now i need to hide some part inside page.php, that should hide from mobile version, and appeared in desktop version only

i already tried add this define code inside templatedesktop.php file :

define(‘THIS_SCRIPT’, ‘templatedesktop’);

and wrap some part that want to hide

if (THIS_SCRIPT == ‘templatedesktop’)
{
some part that want to hide
}

but its not working, maybe its should do the opposite, please help what is the right if conditional/methode? like request, referer or other