<form class="form-inline" role="form" action="send-tel.php" target="_blank" method="post" name="form">
<div class="form-group">
<input type="tel" class="form-control" id="tel" placeholder="000-000-00-00" pattern="^\d{3}-\d{3}-\d{2}-\d{2}$" name="telephone" required="required">
</div>
<button type="submit" class="btn btn-danger" name="button">Перезвоните мне</button>
</form><input class="phone-mask" name="phone" type="text"><html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="jquery.mask.js"></script>
</head>
<body>
<input class="phone-mask" name="phone" type="text">
<script type="text/javascript">
$.jMaskGlobals = {translation: {
'n': {pattern: /\d/},
}
};
$('.phone-mask').mask('+380nn-nnn-nnnn').val('+380');
</script>
</body>
</html><input id="phone" value="+380">$('#phone').on('input',function(){
var val = this.value;
if(val.length<4)
this.value = '+380';
});
