Checking Events for Modifier Keys : Key Event « Event « JavaScript DHTML

Checking Events for Modifier Keys

JavaScript Bible, Fourth Edition
by Danny Goodman 

John Wiley & Sons CopyRight 2001
<TITLE>Event Modifiers</TITLE>
function checkMods(evt) {
    evt = (evt) ? evt : (window.event) ? window.event : ""
    if (evt) {
        var elem = ( ? : evt.srcElement
        var form = document.output
        if (evt.modifiers) {
            form.modifier[0].checked = evt.modifiers & Event.ALT_MASK
            form.modifier[1].checked = evt.modifiers & Event.CONTROL_MASK
            form.modifier[2].checked = evt.modifiers & Event.SHIFT_MASK
            form.modifier[3].checked = evt.modifiers & Event.META_MASK
        } else {
            form.modifier[0].checked = evt.altKey
            form.modifier[1].checked = evt.ctrlKey
            form.modifier[2].checked = evt.shiftKey
            form.modifier[3].checked = false
    return false
<H1>Event Modifiers</H1>
<P>Hold one or more modifier keys and click on 
<A HREF="javascript:void(0)" onMouseDown="return checkMods(event)">
this link</A> to see which keys you are holding.</P>
<FORM NAME="output">
<P>Enter some text with uppercase and lowercase letters:
<INPUT TYPE="text" SIZE=40 onKeyUp="checkMods(event)"></P>
<P><INPUT TYPE="button" VALUE="Click Here With Modifier Keys" onClick="checkMods(event)"></P>
<INPUT TYPE="checkbox" NAME="modifier">Alt
<INPUT TYPE="checkbox" NAME="modifier">Control
<INPUT TYPE="checkbox" NAME="modifier">Shift
<INPUT TYPE="checkbox" NAME="modifier">Meta


Related examples in the same category

1.'ctrlLeft' Example
2.'ctrlKey' Example
3.'shiftKey' Example
4.'shiftLeft' Example
5.'keyCode' Example
6.Catches and manages the keyboard's events
7.Key and Character Codes vs. Event Types
8.Shift key pressed?
9.Unicode of the key pressed
10.Keyboard Event Handler Laboratory
11.Displaying keyCode Property Values
12.Displaying charCode and keyCode Property Values
13. Checking Events for Key and Mouse Button Pressed
14.Handle arrow key, control, alt
15.Get key code in key down event (IE)
16.Press F1 to trigger the help event