trying to lock my linksey router but dont know my WPA key? how do find ths?

I'd suggest a direct LAN connection followed by a factory reset.

no probs sorted it

trying to lock my linksey router but dont know my WPA key? how do find ths?

You can't - it's part of the standard that it shouldn't be visible.

You will have do as Ap0gee says and enter a new one. Any wireless connections will be dropped and will need to be reconfigured.

For maximum security, visit a site such as https://www.grc.com/passwords.htm to create a secure password