<!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>
<title>使用正则表达式</title>
<script language=javascript>
function ValidateNumber(number)
{
//电话号码的正则表达式
var pattern=/^021-\d{8}$/;
//进行测试
var result=pattern.test(number);
//检查测试结果
if(result==true)
alert("合法的上海电话号码");
else
alert("非法的上海电话号码");
}
</script>
</head>
<body>
<form>
<table>
<tr>
<td>
请输入电话号码:
</td>
<td>
<input type=text id="NUMBER" name="NUMBER" />
</td>
</tr>
<tr>
<td colspan=2>
<input type=button value="验证" onclick="ValidateNumber(NUMBER.value)" />
</td>
</tr>
</table>
</form>
</body>
</html>