<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD> <script type="text/javascript"> function check() { var val = document.getElementById("test").value; var reg = /^(?!(__|--|\.\.))([a-z0-9_.\-])+[a-z0-9]$/g; alert(reg.test(val)); }
<HTML>
<HEAD>
<script type="text/javascript">
function check() {
var val = document.getElementById("test").value;
var reg = /^(?!(__|--|\.\.))([a-z0-9_.\-])+[a-z0-9]$/g;
alert(reg.test(val));
}
</script>
</head> <BODY>
<input type="text" id="test" onblur="check()" />
</BODY>
</HTML>
正解!