<script language=vbscript>
...
aa=...
if len(trim(aa))<>10 then
msgbox "有误"
else
if left(aa,4)<>"5278" then
msgbox "有误"
end if
end if
...</script>
...
aa=...
if len(trim(aa))<>10 then
msgbox "有误"
else
if left(aa,4)<>"5278" then
msgbox "有误"
end if
end if
...</script>
<head>
<title>数字验证</title>
</head>
<body>
<script >
function regex()
{
var regex=/^5278\d{6}$/g;
var str = document.form1.name1.value;
var result = regex.test(str);
alert(result);
}
</script>
<form name=form1>
<input type=text name=name1 >
<input type=button onClick="regex()" value="test">
</form>
</body>
</html>