JavaScript » eventhandler » onKeyDown

Syntax:
onKeyDown = myJavaScriptCode

Event handler for Document, Image, Link, TextArea.

The onKeyDown event handler executes the specified JavaScript code or function on the occurance of a KeyDown event. A KeyDown event occurs when the user depresses a key.

The onKeyDown event handler uses the following Event object properties.

type - this property indicates the type of event.
target - this property indicates the object to which the event was originally sent.
layerX - the cursor location when the KeyDown event occurs.
layerY - the cursor location when the KeyDown event occurs.
pageX - the cursor location when the KeyDown event occurs.
pageY - the cursor location when the KeyDown event occurs.
screenX - the cursor location when the KeyDown event occurs.
screenY - the cursor location when the KeyDown event occurs.
which - this represents the key pressed as its ASCII value.
modifiers - lists the modifier keys (shift, alt, ctrl, etc.) held down when the KeyDown event occurs.

Examples

Code:
<body>
<form action="" method="POST" id="myForm">
<input type="text" name="myText" onKeyDown="changeVal()">

<script type="text/javascript" language="JavaScript">
s1 = new String(myForm.myText.value)

function changeVal() {
     s1 = "You pressed a key"
    myForm.myText.value = s1.toUpperCase()
}

</script>
</form>
</body>
Explanation:

This example shows the use of the onKeyDown event handler to display a message in the text box.

See Also: