Untitled

<html>
    <head>
    <script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
    </head>
    <select>
        <option value="1">One</option>
        <option value="2">Two</option>
    </select>
    <input type="text" name="bal" id="textbal" onchange="Change()"/>
    <script type="text/javascript">
            $('select').on('change', function() {
              $('#textbal').val( this.value );
              debugger;
              var a = this.value;

              alert(a);

              $('#textball').attr('value',a);
              $('#textbal').trigger('change');
            });

            function  Change()
            {
               alert('Hii');
            }
    </script>
    </html>