function checkKey(e)
{
if (window.keycode != 27) {
alert("Your return key has been disabled");
return false
}
}

This one is simple enough, except that the key codes are not the same for IE and netscape,you should check them if you ever need them

 

Type something...

This keypress function is not working for NS6

 

Same Modifiers:

alt = 1
control = 2
alt + control = 3
shift = 4
alt + shift = 5
control + shift = 6<
alt + control + shift = 7

apple keys

meta = 8
meta + alt = 9
meta + control = 10
meta + alt + control = 11
meta + shift = 12
meta + alt + shift = 13
meta control + shift = 14
meta + alt + control + shift = 15