A simple implementation method to prohibit the input of certain symbols in the form of the web page. For example, the following code prohibits the input of: "*", "^" and "|" three symbols
<!DOCTYPE html PUBLIC "-//W3C// DTD XHTML 1.0 Transitional//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html xmlns=" http://www.w3.org/1999/xhtml ">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>Untitled 1</title>
</head>
<body>
<input onkeyup="this.value=this.value.replace(/[*^|]+/,'');" value="" size="20" />
</body>
</html>