<html>
<head>
<script>
var phone_value = document.getElementById('phone_mobile');
function newDoc() {
window.location.assign('https://web'+phone_value+'.com');
}
</script>
</head>
<body>
<input type="number" id="phone_mobile" />
<input type="button" value="Load new document" onclick="newDoc()">
</body>
</html>
Средний
