Play with JavaScript: Capturing Control Keys

< html >
< head >
< script language = "JavaScript" > function testCtrlKeys(e)
{
    //Create an array for all possible keys
    var arrCtrlKeys = new Array('a', 'n', 'c', 'x', 'v', 'j');
    var key;
    var isCtrl;

    if (window.event)
    {
        key = window.event.keyCode; //Valid only for Internet Explorer
        if (window.event.ctrlKey) isCtrl = true;
        else isCtrl = false;
    } else
    {
        key = e.which; //this is other than IE
        if (e.ctrlKey) isCtrl = true;
        else isCtrl = false;
    }


    //if ctrl is pressed check if other key is in forbidenKeys array
    if (isCtrl)
    {
        for (i = 0; i < arrCtrlKeys.length; i++)
        {
            //case-insensitive comparation
            if (arrCtrlKeys[i].toLowerCase() == String.fromCharCode(key).toLowerCase())
            {
                alert('You have pressed CTRL + ' + String.fromCharCode(key) + '.');

                return false;
            }
        }
    }
    return true;
} < /script>

</head >
< body >
< form method = "" >
< div > < h3 > Test Key Combinition[Ctrl + A, Ctrl + N, Ctrl + C, Ctrl + X, Ctrl + V, Ctrl + J] < /h3>
<input type="text" name="mytext"
onKeyPress="return testCtrlKeys(event);"
onKeyDown="return testCtrlKeys(event);" / >
< /div>
</body >
< /html>