Ipad and Iphone with ZyXEL Wifi

I have a ZyXEL ZyAIR G-1000 wifi router.
I am unable to connect both Iphone and Ipad to this router.
I have entered the mac address (Wifi address) on the filtering system and entered the password with not luck.
Can anyone help me.
Have also email ZyXEL as well hoping for answer there.

Cheers