正则表达式验证老是失败
<body>
<?php
if(!empty($_POST[sub]))
{
if(ereg("\d{10}", $_POST[username]))
{echo "验证通过。";}
else
{echo "验证失败";}
}
?>
<form action="" method="post">
用户名<input type="text" name="username"><br>
<input type="submit" name="sub" value="提交">
</form>
</body>
