function isMobile() {
var mobile = document.getElementById("mobile_phone");
var num = mobile.value;
var reg = /^(13[0-9]|186|188|150|151|158|159|147)/d{8}$/;
if(num == "") {
alert("請輸入完整的手機號");
mobile.focus();
return false;
} else if (reg.test(num)) {
alert("輸入的手機號格式正確");
} else {
alert("請輸入正確的11位手機號碼");
mobile.focus();
return false;
}
}
function isEmail() {
var email = document.getElementById("email");
var email_value = email.value;
if(email_value == "") {
alert("請輸入完整的郵箱");
email.focus();
return false;
} else {
var reg = /^[a-zA-Z0-9](/w)+@(/w)+(/.)+(com|com/.cn|net|cn|net/.cn|org|biz|info|gov|gov/.cn|edu|edu/.cn)$/;
if(reg.test(email_value)) {
alert("輸入的郵箱格式正確");
} else {
alert("請輸入正確的郵箱格式");
email.focus();
return false;
}
}
}
function isPhone() {
var phone = document.getElementById("phone");
var phone_value = phone.value;
if(phone_value == "") {
alert("請輸入完整的座機號碼");
phone.focus();
return false;
} else {
var reg = /^[(]?0/d{2,3}[)]?/s*[-]?/s*/d{7,8}$/; //010-87989898 01098989898 (0712)8989898 010 - 23343434 這些格式的座機號碼都滿足
if(reg.test(phone_value)) {
alert("輸入的座機號碼正確");
} else {
alert("輸入的座機號碼格式錯誤");
phone.focus();
return false;
}
}
}

<p>
<label for="mobile_phone">手 機</label>
<input type="text" id="mobile_phone", name="mobile_phone" value="15107105287" />
<input type="button" value="validate" onclick="isMobile()" />
</p>
<p>
<label for="phone">座 機</label>
<input type="text" id="phone" name="phone" value="027-87767676" />
<input type="button" value="validate" onclick="isPhone()" />
</p>
<p>
<label for="email">郵 箱</label>
<input type="" id="email" name="email" value="zhangchen2397@126.com" />
<input type="button" value="validate" onclick="isEmail()" />
</p>