Javascript keypress results in action

This javascript I used to catch a keystroke and perform an action.
It works in Firefox and IE.

Example
(javascript)
document.onkeypress=keyPressed;

function keyPressed(e){
var keyCode=(e)? e.which :event.keyCode;
if(keyCode==122)
calculateScore("One")
if(keyCode==109)
calculateScore("Two")
if(keyCode==113)
keyWinner("One")
if(keyCode==112)
keyWinner("Two")
if(keyCode==97)
checkUndo("One")
if(keyCode==108)
checkUndo("Two") }