我正在尝试验证jsp登录表单，我需要字段（标签）验证而不是警报消息

Question

Here is my javascript:

function checkEmail() {

    var email = document.getElementById('mLoginName');


    var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})|([0-9]{10})+$/;


    if (!filter.test(email.value)) {
        alert("Please enter valid email id or 10 digit mobile number");
        email.focus();
        return false;
    }
}

HTML Code:

<form:form method="post" onsubmit="return checkEmail();" action="SignIn"  modelAttribute="memberBean" >
    <form:input type='hidden' name='mode' id='mode' path='mode' />
    <form:input type='text'  class="input" name='mLoginName'  id='mLoginName' path='mLoginName' onblur="checkInp()" placeholder='Email/Mobile' />

<input type='submit' class="submit" value='SignIn/SignUp' >
</form:form>

Answer 1

You can just add a <span id="mLoginValidate"></span> ( or a <p></p> depending on how you want it to look ) after your input, and then in your code, add

document.getElementById('mLoginValidate').innerHTML = "Please enter valid email id or 10 digit mobile number";

You can also change its css to display: none when the user starts re-typing, and then change it back do display: block upon failed validation.

Here's a little fiddle: https://jsfiddle.net/virginieLGB/h600vecx/

Here's what I've done:
HTML:

<input type='text'  ... onkeydown="hideError()" />
<span id="mLoginValidate">Please enter valid email id or 10 digit mobile number</span>

CSS:

span {
  color: red;
  display: none;
}

JAVASCRIPT:

function hideError() {
    document.getElementById("mLoginValidate").style.display = "none";
} 

And in your checkEmail() function :

document.getElementById("mLoginValidate").style.display = "block";