jQuery Append

I'm trying to append the following however when I do it shows it then takes it a way in under a second, can some tell me why?

<script type="text/javascript">
$(document).ready(function(){
    $("#button").click(function() {
         var fname = $("input#fname").val();
         var lname = $("input#lname").val();
         var dataString = 'fname='+ fname + '&lname=' + lname;
         $.ajax({
              type: 'POST',
              data: dataString,
            success: function(display){
                    $('.inner').css("display","inline").append(fname);
               },

        });
    });

});

</script>

Code (markup):

 

Its like the page is refreshing.

 

Worked it out just needed to add

onclick="return(false)"

Code (markup):

to the input.