If you don’t know which one you should use

Default Tx Key	You can set up to four sets of WEP key, and you
	can decide which key is being used by default here.
	If you don’t know which one you should use,
	select ‘Key 1’.
Encryption Key 1	Input WEP key characters here, the number of
to 4	characters must be the same as the number
	displayed at ‘Key Format’ field. You can use any
	alphanumerical characters (0-9, a-z, and A-Z) if
	you select ‘ASCII’ key format, and if you select
	‘Hex’ as key format, you can use characters 0-9,
	a-f, and A-F. You must enter at least one encryption
	key here, and if you entered multiple WEP keys,
	they should not be same with each other.
Enable 802.1x	Check this box to enable 802.1x user
Authentication	authentication. Please refer to Section 2-7-5 for
	detailed instructions.

After you finish with setting, please click ‘Apply’, and the following message will be displayed:

When you see this message, the settings you made is successfully save. You can click ‘Continue’ button to back to previous page and continue on other setting items, or click ‘Apply’ button to restart the wireless access point and the changes will take effect after about 30 seconds.

If you don’t know which one you should use,

select ‘Key 1’.