Edit in JSFiddle

Result
JavaScript
HTML

jQuery2 = jQuery.noConflict(true);

$(function(){
    $("#fff").keypress(function(event) { 
        if (event.which == 13) { $('<div>jQuery</div>').appendTo(document.body); } 
    });

    jQuery2("#fff").keypress(function(event) {
        if (event.which == 13) { $('<div>jQuery2</div>').appendTo(document.body);  }
    });

    var ev = new Event('keypress');
    ev.keycode = 13;
    ev.which = 13;
    
    document.getElementById('fff').dispatchEvent(ev);
    
});

<script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
<script src="http://code.jquery.com/jquery-1.7.2.min.js"></script>
<body>
    <input type="text" id="fff" style="width:100px"/>
</body>