Where is the"IRS" button?

[Fonur]

Huys, really I can't find the IRS button to switch it to "NAV" to continiue the precedure :(  

I have only the IRS button which is only have "Both L" and "Both R " option but not "NAV" !

 

If I can find where is NAV I will activate it to make FMC show IRS POS to configure it

 

 

[Mike71011]

its on the Overhead panel right above your head. if you follow the first column  up to FLT CONTROL and keep going up towards the seconday overhead panel you will see the IRS switches

it should look like this 

[teopereira]

Or the 2d aft overhead panel