vbulletin option in a condition

[Scanu]

Hi ebery one i have some problem with a code

PHP Code:

if ($show['OPTION']) 


OPTION is the option that the user select by the admincp..
now i have create the option and here we have

PHP Code:

. $vbulletin->options['var_field'] . 


Now I put into the code and will be this

PHP Code:

if ($show['' . $vbulletin->options['var_field']. '']) 


The problem: doesn't work D:
Where i'm wrong?