JavaScript: Basic validator form validation

Basic validator form validation

function formValidation() {
    jQuery.validator.addMethod("twowords", function(value, element) {
        var tagCheckRE = new RegExp("(\\w+)(\\s+)(\\w+)");
        return tagCheckRE.test(value);
    }, "At least two words.");


    var numInputFieldsToCheck =
        $('#contactForm').find('input').length -1 +
        $('#contactForm').find('textarea').length;
    var indexOfErrorShowing = 0;
    var showErrors = false;

    var validatorContact = $('#contactForm').validate({

        onfocusout: function(element, event){
            $(element).valid();
        },

        showErrors: function (errorMap, errorList) {

            indexOfErrorShowing++;

            if (!Modernizr.input.placeholder && indexOfErrorShowing > numInputFieldsToCheck) {
                showErrors = true;
            } else if (Modernizr.input.placeholder) {
                showErrors = true;
            }

            if (showErrors) {
                $("#errorCon").html("<p>Wypełnij prawidłowo wymagane pola</p>");

                if (this.numberOfInvalids() > 0) {
                    $("#errorCon").css('visibility', 'visible');
                } else {
                    $("#errorCon").css('visibility', 'hidden');
                }

                this.defaultShowErrors();
            }
        },

        errorPlacement: function () {
            return false;
        },
        
        rules: {
            name: {
                required: true,
                twowords: true
            },
            email: {
                required: true,
                email: true
            },
            telephonenumber: {
                digits: true,
                minlength: 7
            },
            subject: {
                required: true
            },
            message: {
                required: true
            }
        },
       messages: {
           name: {
               required: 'Please fill in your name',
               twowords: 'Please fill in your full name'
           },
           email: {
               required: 'Please fill in your email',
               email: 'It is not a valid email'
           },
           telephonenumber: {
               digits: 'Please only fill in numbers',
               minlength: 'Please fill in your full phone number'
           },
           subject: {
               required: 'Please fill in a subject'
           },
           message: {
               required: 'Please fill in your message'
           }
       }
  });
}