html - JQuery: Operations on output value, but still keeping it printing as user types -

in html have this:

 <input type="text" name="earned" id="earned">    <p>you have: $<span id="amount"></span></p> 

and in javascript file have this:

$(function(){     $('#earned').keyup(function(){         var $earned = this;         $earned = $earned/100;         $('#amount').text($(earned).val()+ '.00');     }); }); 

i wrote code simple calculator. if wanted grab user typing , change typed, how go this? how come dividing 100 doesn't work? outputs number being typed in.

$('#earned').keyup(function(){     var $earned = parseint($(this).val(), 10)/100; // .val() here     $('#amount').html($earned+ '.00'); // variable here }); 

the this refers dom input field. need jquery object of , .val() of input field. parse integer, because strings can't divided. , set output span.