Wifi password

[#1]

At first I needed tu log in to my wifi network with a password. Now I don't, andI haven't changed any settings. I'm worried anyone could be using my network now. What can I do?

[#2]

What device are you using? It may well have saved the password for you.

[#3]

Either the device you are connecting has remembered the password or the password has been removed from the router.
Log into the router's configuration screen and check the WiFi set-up.
Edit: I've been beaten to it

[#4]

Maybe yours is a 585 v8 like mine. It keeps the same password no problem but every time you turn on wifi you get three options down the bottom.
Disabled
Use WEP Encryption
Use WPA-PSK Encryption
As you've probably guessed it always defaults to disabled. So you have to remember to select the one that suits you.

[#5]

I can see that you do have a v8, have you perhaps tried resetting to the WPA key (wireless password) to something memorable on the router then enter that into your wireless devices?