Московский номер телефона

<input id="online_phone" name="phone" type="tel" maxlength="50" autofocus="autofocus"
							required="required" value="+7(___)___-__-__"
							pattern="\+7\s?[\(]{0,1}9[0-9]{2}[\)]{0,1}\s?\d{3}[-]{0,1}\d{2}[-]{0,1}\d{2}"
							placeholder="+7(___)___-__-__">
                              
                              
function setCursorPosition(pos, e) {
	e.focus();
	if (e.setSelectionRange) e.setSelectionRange(pos, pos);
	else if (e.createTextRange) {
		var range = e.createTextRange();
		range.collapse(true);
		range.moveEnd("character", pos);
		range.moveStart("character", pos);
		range.select()
	}
}

function mask(e) {
	//console.log('mask',e);
	var matrix = this.placeholder,// .defaultValue
		i = 0,
		def = matrix.replace(/\D/g, ""),
		val = this.value.replace(/\D/g, "");
	def.length >= val.length && (val = def);
	matrix = matrix.replace(/[_\d]/g, function (a) {
		return val.charAt(i++) || "_"
	});
	this.value = matrix;
	i = matrix.lastIndexOf(val.substr(-1));
	i < matrix.length && matrix != this.placeholder ? i++ : i = matrix.indexOf("_");
	setCursorPosition(i, this)
}
window.addEventListener("DOMContentLoaded", function () {
	var input = document.querySelector("#online_phone");
	input.addEventListener("input", mask, false);
	input.focus();
	setCursorPosition(3, input);
});