<form action="" class="form" action="" method="post" id="form1">
<div class="mt20">
<label for="name" class="namelabel">您的姓名：</label><br>
<input type="text" placeholder="請輸入您的姓名..." class="write write1" id="username" />
</div>
<div class="mt20">
<label for="name" class="namelabel">聯系電話：</label><br>
<input type="tel" placeholder="請輸入您的手機號碼..." class="write write2" id="tel

</form>

<script type="text/javascript">
function sb(){
var username = document.getElementById("username");
var tel = document.getElementById("tel");
var rules = /^1[3,5]\d{9}$/;
if(username.value==null || username.value==""){
alert("請輸入姓名");
username.focus();
return;
}
if(tel.value==null || tel.value==""){
alert("請輸入手機號");
tel.focus();
return;
}else if(rules.test(tel.value)){
alert(‘是手機號碼‘);
}else {
alert(‘不是手機號碼‘);
}
}

</script>

移動端表單驗證用戶名與手機號