How to click automatically submit button after selecting dropdownlist value

Question

This is my code. How to click automatically submit button after selecting dropdownlist value?

<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" method="GET" name="form1" class="style1" id="form1">
  <p align="center">Select Section 
    <select name="section" required ><option selected="selected" disabled="disabled">Select Section</option>
    <option>ALL</option>
    <option>RWS</option>
    <option>Structure</option></select>
    From
    <input name="fromdate" type="date" placeholder="YYYY-DD-MM" required id="mydate" data-lang="en" data-years="2014-2050" data-format="YYYY-MM-DD"/>
    To   
  <input name="todate" type="date" placeholder="YYYY-DD-MM" required id="mydate1" data-lang="en" data-years="2015-2055" data-format="YYYY-MM-DD"/>
  <input name="submit" type="submit" id="submit" value="SHOW" />
  </p>

Answer 1

You will need to bind onchange event and call submit method of the HTMLFormElement:

$('#form1 select').on('change', function() {
    this.form.submit();
});

Important detail. Rename your submit button, you don't want it to have name submit because this.form.submit will point to HTMLButtonElement object in this case, while you want it to be a submit methods of the form element:

<input name="submit-btn" type="submit" id="submit-btn" value="SHOW" />

Demo: http://jsfiddle.net/dfsq/vkadz4cu/

Answer 2

You have not given dropdown code here, hence I am assuming and writing:

<select name="drpdwn" onclick="submitForm()">
   <option value="opt1">Option1</        option>
 <option value="opt2">Option2</option>
 </option>

 <script>
 function submitForm(){
              document.getElementById('formid').submit();

   }


   </script>

Answer 3

Seem you want to trigger event click on the button.

$('#form1 select').on('change', function() {
    $('#submit').trigger('click');
});