How to get the sucess message in the same page after submitting the contact form?

try this way . try to send mail from an ajax . Please write your code like below

javascript

    <script type="text/javascript">
    function sendEnquiryform(){
        var name=$('#name').val();
        var email=$('#email').val();
        var message=$('#message').val();
        $.post("send_mail.php",'name='+name+'&email='+email'&message='+message,function(result,status,xhr) {
                if( status.toLowerCase()=="error".toLowerCase() )
                { alert("An Error Occurred.."); }
                else { 
                    //alert(result);
                    $('#sucessMessage').html(result);
                }
            })
            .fail(function(){ alert("something went wrong. Please try again") });
    }
</script>

Your html

<form method="post" name="FrmEnquiry" id="FrmEnquiry" action="" onsubmit="sendEnquiryform();">
    <input name="name" id="name" required="required" placeholder="Your Name">
    <input name="email" id="email" type="email" required="required" placeholder="Your Email">

    <div class="clearfix"> </div>
    <textarea name="message" id="message" cols="20" rows="5" required="required" placeholder="Message"></textarea>
    <div class="submit">
        <input id="submit" name="submit" type="submit" value="Submit">
    </div>
</form>

<span id="sucessMessage"> </span>

send_mail.php

<?php
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $from = 'From: agriindiaexp.com'; 
    $to = '[email protected]'; 
    $subject = 'Email Inquiry';

    $body = "From: $name\n E-Mail: $email\n Message:\n $message";

    if ($_POST['submit']) {
        if (mail ($to, $subject, $body, $from)) { 
           $success = "Message successfully sent";
        } else {
            $success = "Message Sending Failed, try again";
        }
    }
?>

this will display your message in your page.Please try this. This is working fine in my case.

You could post the form to the same page and check for a success message there, like this.

<?php

if ($_POST['submit']) {
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $from = 'From: agriindiaexp.com'; 
    $to = '[email protected]'; 
    $subject = 'Email Inquiry';

    $body = "From: $name\n E-Mail: $email\n Message:\n $message";
    if (mail ($to, $subject, $body, $from)) { 
       $success = "Message successfully sent";
    } else {
        $success = "Message Sending Failed, try again";
    }
}
?>

...other html....

<div id="message"><?php if(isset($success)){ echo $message; } ?></div>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
    <input name="name" required="required" placeholder="Your Name">
    <input name="email" type="email" required="required" placeholder="Your Email">

    <div class="clearfix"> </div>
    <textarea name="message" cols="20" rows="5" required="required" placeholder="Message"></textarea>
    <div class="submit">
        <input id="submit" name="submit" type="submit" value="Submit">
    </div>
</form>

...other html....