How to disable dial lock without password

I am using panasonic PANASONIC KX-TG2620BX and was locked by my daughter. We had it unlocked by:
press MENU
select Dial lock
Enter password 1234
Press save
Turn off Dial lock? press yes

For the KX-TGA181AL

The "small inverted triangle" flashing in the bottom left hand corner of the screen indicates that -

the handset is too far from the base.
The AC adaptor is not connected
High electrical inteference
The handset registration is canceled

I presume that all is well with the base which leaves the handset registration. to reregister.

Press the OK button.
Press the down button (Setting HS should now be displayed)
press OK
Press the down button untill REGISTRATION is displayed
Press OK

on the base unit press and hold the ittle button on the left side of the base unit for about 5 sec.

On the handset press up or down to select a base unit number.
Wait untill BS PIN is displayed
Enter the Base unit Pin no. defalut is 0000
A confirmation tone will sound and the triangle should have stopped flashing.

that should sort it out,

BTW to lock and unlock the handset press and hold the OK button for 2 secs