How to make default 1 by entering field IMAE/SN

How to make default 1 by entering field IMAE/SN

Hello Guys, i need some help to debug my javascript in localhost running well but only first row so i upload in jsfidlle but it doesn't work >.< 

all i need is how to make default fields Jumlah to be 1 when user enter IMAE/S.N

my script about it in bellow 


Reminder :Localhost running first row but next row not working in jsfiddle not work, Thanks for respon my jsfiddle here  http://jsfiddle.net/dauruk0512/08ps55uf/11/
  1. $(document).on('keyup', '.imae', function() {
  2.           var imae = $(this).val();
  3. if (imae!='')
  4.           {
  5.          
  6. $(".quantity").val(1);
  7. $(".quantity").prop("readonly", true);
  8. }
  9.           else 
  10.           {
  11. $(".quantity").val("");
  12. $(".quantity").prop("readonly", false);
  13.           }
  14.       })