Definition and Usage
The onkeydown event occurs when a keyboard key is pressed or held down.
Syntax
onkeypress="SomeJavaScriptCode" |
| Parameter | Description |
| SomeJavaScriptCode | Required. Specifies a JavaScript to be executed when the event occurs. |
Supported by the following HTML tags:
| <a>, <acronym>, <address>, <area>, <b>, <bdo>, <big>, <blockquote>, <body>, <button>, <caption>, <cite>, <code>, <dd>, <del>, <dfn>, <div>, <dt>, <em>, <fieldset>, <form>, <h1> to <h6>, <hr>, <i>, <input>, <kbd>, <label>, <legend>, <li>, <map>, <object>, <ol>, <p>, <pre>, <q>, <samp>, <select>, <small>, <span>, <strong>, <sub>, <sup>, <table>, <tbody>, <td>, <textarea>, <tfoot>, <th>, <thead>, <tr>, <tt>, <ul>, <var> |
Supported by the following JavaScript objects:
| document, image, link, textarea |
Tips and Notes
Browser differences: Internet Explorer uses event.keyCode to retrieve the character that was pressed and Netscape/Firefox/Opera uses event.which.
Example
In this example the user cannot type numbers into the input field:
<html>
<body>
<script type="text/javascript">
function noNumbers(e)
{
var keynum;
var keychar;
var numcheck;if(window.event) // IE
{
keynum = e.keyCode;
}
else if(e.which) // Netscape/Firefox/Opera
{
keynum = e.which;
}
keychar = String.fromCharCode(keynum);
numcheck = /\d/;
return !numcheck.test(keychar);
}
</script><form>
<input type="text" onkeypress="return noNumbers(event)" />
</form> </html> |
