2001 Mitsubishi Montero Audio Reset

2001 Mitsubishi Montero 6 cyl Two Wheel Drive Automatic 150K miles

I replaced the battery in my 2001 Mopntero Sport and the System requires entry of the Anti Theft Code which I have.

The radio display says "OFF" and I can't get it to request entry of the code.

How do I get the radio to default into the code entry condition?

Thanks