internal phone input
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<link href="https://cdnjs.cloudflare.com/ajax/libs/intl-tel-input/11.0.14/css/intlTelInput.css" rel="stylesheet" />
<script src="https://code.jquery.com/jquery-1.11.1.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/intl-tel-input/11.0.14/js/utils.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/intl-tel-input/11.0.14/js/intlTelInput.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.mask/1.14.11/jquery.mask.js"></script>
<form action="" method="POST" onsubmit="return submitForm(this);">
<input type="tel"name ="phone1" id="phone1" value="<?php echo $phone1;?>">
<input type="tel" class="hide" id="hiden">
<button type="submit">Validate</button>
</form>