javascript - how to check if period sign(.) is removed from the word in textbox in jQuery? -

i want know if possible hit event if period sign . removed textbox. example have textbox#quantity takes numeric values input period sign

and have drop down control#unitvalue have 3 option

i had hit event on period sign . key press follows

$("#quantity").keypress(function(e) {     if(e.which == 46) {         //successfully disabled gram in unit     } });  

now want enable "gram" option in drop down if period sign . removed textbox. have idea don't if right so. idea is:- on key press add each letter array, on backspace key press, check if letter on array index period sign . or not if . sign enable "gram"

any appreciated

thank you

js fiddle - updated -using .prop() instead

// attach functionality on multi events  $('#inpt').on('keypress input change', function() {    var gram = $('#slct').children('[value="1"]');      // if indexof "." > -1, there's dot     if ($(this).val().indexof('.') > -1) {        // disable gram option      gram.prop('disabled', true);        // ====================== part added @sarathchandra       // reset drop down if gram option selected      if ($('#slct').val() === "1" || $('#slct').val() === null) {        $('#slct').val("0");      }        // ====================== @sarathchandra thank improvement      } else {        // if dot removed, set disabled prop false      gram.prop('disabled', false);    }  });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>  <input id="inpt" type="text">  <select id="slct">    <option value="0">- select -</option>    <option value="1">gram</option>    <option value="2">kilo</option>    <option value="3">quntal</option>  </select>

---

edit: @sarathchandra added these couple lines:

if($('#slct').val() == "1" || $('#slct').val() == null){       $('#slct').val("0"); } 

to fix when entered value doesn't contain ., , gram selected then period add, resets dropdown.