JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <head>
        <title>
            Test jQuery
        </title>            
        <script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.9/jquery.validate.js"></script>
    </head>
    <body>
        <form id="myform">
            Text1: <input type="text" id="text1" name="text1" size="10" /><br>                
            Text2: <input type="text" id="text2" name="text2" size="10" /><br>
            <input type="button" id="submitbutton" value="Validar" type="submit"/>
            <br>    
            <span id="validationStatus"/>
        </form>
    </body>
</html>

CSS

span {
  color: green;
}

span.invalid {
  color:red;
}

JavaScript

$(document).ready(function() {

        var _formRules = {
            text1: {
                required: function(elem) {
                    var text2_value = $("#text2").val();
                    return ($.trim(text2_value).length <= 0);
                }
            },
            text2: {
                required: function(elem) {
                    var text1_value = $("#text1").val();
                    return ($.trim(text1_value).length <= 0);
                }
            }
        };
                        
        var _errorMessages = {
            text1: {
                required: ""
            },
            text2: {
                required: ""
            }
        }                
                        
        $("#submitbutton").click(function() {                    
            var _handler = $("#myform").validate({
                rules: _formRules,
                messages: _errorMessages
            });
            
            var status = $("#validationStatus");                         
        
            if(_handler.checkForm()) {
                status.removeClass("invalid");
                status.text("validation ok!");
            } else {
                status.toggleClass("invalid");
                status.text("Pelo menos um campo deve ser preenchido!");
            }                     
        });
});