자바스크립트 동시 입력이 왜 안될까요?

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<script type="text/javascript">

$(document).ready(function(){

    $("#costomerPrice").keyup(function(){
        $("#price").text($("#costomerPrice").val());
    });

});

</script>

 

 

<form name="myform" action="**" method="post"  enctype="multipart/form-data" onSubmit="return formsubmit();">
 
<input type="text" name="costomerPrice" id="costomerPrice" value=""  class="input" style="width:80px;"    />
<input type="text" name="price" value="" id="price" class="input" style="width:80px;"  />