根据其他输入值输入实时计算

I am working on live currency calculator script, goal is to make live calculations based on form inputs.

so far thanks to your comments i achieved bellow:

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="usd">
<input type="text" id="gel">
<input type="text" id="eur">

JAVASCRIPT

<script>
$("#gel").keyup(function(){
  var val = $(this).val();
  if(isNaN(val)) { val =val.replace(/\D/g,''); }
  $('#usd').val(val / <?php echo $usd; ?>);
  $("#gel").val(val);
  $("#eur").val(val / <?php echo $eur; ?>);
});
$("#usd").keyup(function(){
  var val = $(this).val();
  if(isNaN(val)) { val =val.replace(/\D/g,''); }
  $('#usd').val(val);
  $("#gel").val(val*<?php echo $usd; ?>);
  $("#eur").val(val*<?php echo $usd; ?>/<?php echo $eur; ?>);
});
$("#eur").keyup(function(){
  var val = $(this).val();
  if(isNaN(val)) { val =val.replace(/\D/g,''); }
  $('#usd').val(val*<?php echo $eur; ?>/<?php echo $usd; ?>);
  $("#gel").val(val*<?php echo $eur; ?>);
  $("#eur").val(val);
});
</script>

Is it correct way of doing this ?

//html

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="usd">
<input type="text" id="gel">
<input type="text" id="inr">

//Jquery

$("#usd").keyup(function(){
  var val = $(this).val();
  val = val.replace(/\D/g,'');
  $('#usd').val(val);
  $("#gel").val(val*55);
  $("#inr").val(val*10);
});

You need to use jquery script as follow

$("#usd").change(function(){
  var val = $(this).val();
  $("#gel").val(val*55);
  $("#inr").val(val*10);
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="usd">
<input type="text" id="gel">
<input type="text" id="inr">

</div>