Phone number validation in jQuery with masking

jquery-phone-number-validation.js

//Only integer allowed
jQuery.fn.inputFilter = function(inputFilter) {
    return this.on("input keydown keyup mousedown mouseup select contextmenu drop", function() {
        if (inputFilter(this.value)) {
            this.oldValue = this.value;
            this.oldSelectionStart = this.selectionStart;
            this.oldSelectionEnd = this.selectionEnd;
        } else if (this.hasOwnProperty("oldValue")) {
            this.value = this.oldValue;
            this.setSelectionRange(this.oldSelectionStart, this.oldSelectionEnd);
        } else {
            this.value = "";
        }
    });
};  
(function($){
$(".contact-us-form #phone").inputFilter(function (value) {
        return /^\d*$/.test(value);    // Allow digits only, using a RegExp
      });
      $('.contact-us-form #phone').on( 'keydown focus',function( e){
        e.target.value =  e.target.value.substr( 0, 10) ;
      })
    $('.contact-us-form #phone').on( 'keyup blur',function (e) {
        var x = e.target.value.replace(/\D/g, '').match(/(\d{0,3})(\d{0,3})(\d{0,4})/);
        e.target.value = !x[2] ? x[1] : '(' + x[1] + ') ' + x[2] + (x[3] ? '-' + x[3] : '');

      });
})(jQuery)