you reach the airport and go straight up near the emirates help desk. ask them and they will show you an office. go there fill up a form then go to the bank and take an e-cash card for visa which is 170 riyals. if u have credit card no need taking ecash. go straight to the immigration officer. get ur visa stamped for 30 days. they will give u back a yellow slip. dont throw it cause they will ask you for it when u are flying out.

I went 2 weeks ago.

cheers