javascript - 如何使用javascript显示错误消息而不发出警报

Question

如何使用下面显示的我的代码显示错误消息而不发出警报

函数 validateForm() {

            if (document.getElementById('email').value.trim()=="")
            {
                alert("Please enter your Email");
                document.getElementById('email').focus();
                return false;
            }

            if (document.getElementById('password').value.trim()=="")
            {
                alert("Please enter your Password");
                document.getElementById('password').focus();
                return false;
            }

            }
    </script>

我的表单模型代码如下所示，如何在文本字段下方显示错误消息

 <form  id="register-form" onsubmit ="return validateForm()" action="<?php echo base_url(); ?>Index.php/Login_cntrl/login" method="POST" >

                    <div class="field-wrap">
                        <label class="view-label">Email Address</label>
                        <input type="email" placeholder="Email Address" name="email" id="email" class="input-control" value=""/>

                    </div>

                    <div class="field-wrap">
                        <input type="password" placeholder="Password" name="password" id="password" value="" />



                        <a href="javascript:void(0)" class="btn btn-link btn-nobg" id="btn-show-forgot" >Forgot ?</a>  



                    </div>


                    <div class="field-wrap">
                        <button type="submit" class="btn btn-submit" name="ulogin" id="ulogin" value="ulogin" >Login</button>
                    </div>
                    <div class="field-wrap">
                        <a href="javascript:void(0)" class="btn btn-link btn-nobg" id="btn-show-signup">NEW User? Sign up</a>
                    </div>
                </form>

根据你修改我的代码，但它仍然不起作用

<script>
    function validateForm() {
    if (document.myform.email.value == "") {
    document.getElementById('errors').innerHTML="Please enter a username"; return false;
    }}
    </script>

Answer 1

假设您正在使用 Bootstrap ；您可以使用这样的简单警报消息

HTML

<div id="error" class="alert alert-danger" role="alert"></div>

Javascript

document.getElementById('error').innerHTML="Please enter a username";

将您调用 alert 的所有地方替换为上面的 JavaScript 代码。

引用:http://getbootstrap.com/components/#alerts