Check if Caps Lock is ON (Asp.Net)

checkCapsLock
function checkCapsLock(e) {
var myKeyCode = 0;
var myShiftKey = false;
var myMsg = 'Caps Lock is On.\n\nTo prevent entering your password incorrectly,\nyou should press Caps Lock to turn it off.';

// Internet Explorer 4+
if (document.all) {
myKeyCode = e.keyCode;
myShiftKey = e.shiftKey;

// Netscape 4
} else if (document.layers) {
myKeyCode = e.which;
myShiftKey = (myKeyCode == 16) ? true : false;

// Netscape 6
} else if (document.getElementById) {
myKeyCode = e.which;
myShiftKey = (myKeyCode == 16) ? true : false;

}

// Upper case letters are seen without depressing the Shift key, therefore Caps Lock is on
if ((myKeyCode >= 65 && myKeyCode <= 90) && !myShiftKey) {
alert(myMsg);

// Lower case letters are seen while depressing the Shift key, therefore Caps Lock is on
} else if ((myKeyCode >= 97 && myKeyCode <= 122) && myShiftKey) {
alert(myMsg);

}
}

call:
asp:TextBox ID="txtPassword" runat="server" MaxLength="16" TextMode="Password" onKeyPress="checkCapsLock(event)