<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
</head>
<body>
<input value="" id="tel"> <input value="" > <input value="">
<script>
window.addEventListener("DOMContentLoaded", function() {
function setCursorPosition(pos, elem) {
elem.focus();
if (elem.setSelectionRange) elem.setSelectionRange(pos, pos);
else if (elem.createTextRange) {
var range = elem.createTextRange();
range.collapse(true);
range.moveEnd("character", pos);
range.moveStart("character", pos);
range.select()
}
}
function mask(event) {
var matrix = "+7 (___) ___ ____",
i = 0,
def = matrix.replace(/\D/g, ""),
val = this.value.replace(/\D/g, "");
if (def.length >= val.length) val = def;
this.value = matrix.replace(/./g, function(a) {
return /[_\d]/.test(a) && i < val.length ? val.charAt(i++) : i >= val.length ? "" : a
});
if (event.type == "blur") {
if (this.value.length == 2) this.value = ""
} else setCursorPosition(this.value.length, this)
};
var input = document.querySelector("#tel");
input.addEventListener("input", mask, false);
input.addEventListener("focus", mask, false);
input.addEventListener("blur", mask, false);
});
</script>
</body>
</html>