Javascript验证在codeigniter中不起作用

我正在使用javascript验证html表单。但它不起作用

在脚本编写中，我做了一些基本的验证

下面是我的html表单和javascript验证

请帮帮我哪里做错了

Javascript验证

function register()
    {
        var fname = document.getElementById('fname').value;
        var lname = document.getElementById('lname').value;
        var email = document.getElementById('email').value;
        var contact = document.getElementById('contact').value;
        var pass = document.getElementById('pass').value;      


        var alpha = /^[a-zA-Z\s-, ]+$/;  

        if (fname.value == "") {
        alert('Please enter First Name');
        return false;
         }
        else if (!fname.value.match(alpha)) {
        alert('First Name allows only Alphabets');       
        return false;
         }
        else 
         {
         return true;
         }

    }

HTML表单

<form role="form" method="post" action="" onSubmit="return register();">
    <div class="form-group">
      <label>First Name <span class="mandatory"> *</span></label>
      <input type="text" class="form-control" name="fname" id="fname" placeholder="Enter Your First Name" value="" required>
    </div>
    <div class="form-group">
      <label>Last Name <span class="mandatory"> *</span></label>
      <input type="text" class="form-control" id="lname" name="lname" placeholder="Enter Your Last Name" value="" required>
    </div>
    <div class="form-group">
      <label for="emmail_register">Email address <span class="mandatory"> *</span></label>
      <input id="emmail_register" id="email" name="email" class="form-control" type="text" placeholder="Enter Your Email id" value="" required>
    </div>
    <div class="form-group">
       <label>Contact No. <span class="mandatory"> *</span></label>
       <input type="text" id="contact" name="contact" class="form-control" value="" placeholder="Enter Contact No." required>
    </div>
    <div class="form-group">
       <label>Password <span class="mandatory"> *</span></label>
       <input type="password" id="pass" name="pass" class="form-control" placeholder="Enter your password" value="" required>
    </div>       
    <div class="form-group">
       <input type="submit" onclick="return register();" name="user_register" class="btn btn-primary" value="Create Account">
    </div>          
</form>

名字*
姓*
电子邮件地址*
联络电话*
密码*

无需在

if/else

条件下使用

fname.value

再次获取

值。像这样试试

if (fname== "") {
  alert('Please enter First Name');
  return false;
}
else if (!fname.match(alpha)) {
  alert('First Name allows only Alphabets');       
  return false;
}
else{
  return true;
}

为什么不使用codeigniter表单验证