remap caps lock key to control

[tvn <tvn1981@flashmail.com>]

I used the following in .Xmodmap ,  it behaves somewhat as the control
key except Control (Caps Lock) + a should move to the beginning of the
line, but in my case it doesn't .  The normal Control key works fine
though.  Any idea/suggestion ?  This is a laptop btw, but the keycode
for caps lock is still 66

keycode 66 = Control_L
clear Lock
add Control = Control_L