Checkbox onchange

[dmanghani]

I want to create three checkbox say [] item1, []item2, []item3,
when I press checkbox for item1 the checkbox should stay checked and a input for data opens which when fed in calculates data, If I uncheck the data should disappear.
when I am using input type=submit, the code runs, but I want to do same using onchange or onclick and not have to use submit.
Guidance and help please and if possible a example,
Thanks

[whispers]

You’ll need front end code then… like JS or jQuery.

This part isnt clear to me:

• which when fed in calculates data,

More or less…

you will output/create your page (your HTML markup).

Then add your jQuery code to have listeners check when any of the 3 checkboxes has a ‘change’

You then detect this ‘change’… and then display the hidden input field(s) based on the checkbox change

Whats gets put into the input field… is up to you (not clear)…

Also what type of event(s) you want to trigger the: “calculate this input data” action.

[dmanghani]

Please find enclosed code

<form action ='' method='GET'>
<input  type= 'checkbox' id='instal' name='instal' onchange='this.form.submit()'
<?php  if(isset($_GET['instal'])) { echo 'checked'; } ?>>Install & Comm: 
<input  type= 'checkbox' id='delivery' name='delivery' onchange='this.form.submit()'
<?php  if(isset($_GET['delivery'])) { echo 'checked'; } ?>>Delivery: 
<input  type= 'checkbox' id='discount' name='discount' onchange='this.form.submit()'
<?php  if(isset($_GET['discount'])) { echo 'checked'; } ?>>Discount: 
</form>
<?php
if(isset($_GET['instal'])) {
echo 'Install & Comm';
echo "<form name= 'instal' action ='' method='GET'>";
echo "<input type='decimal'  name='total' size='10' >";
echo "<input type='decimal'  name='ins_gst' size='2' value='' >";
echo "<input type='submit' name='submit' value='Submit' >";
echo "</form>";
$total=$_GET['total'];
$gst=$_GET['ins_gst'];
echo $total;
// Update to mysql ....
} else {
  $total=0;
  $gst=0;
// Update to mysql ....
}
if(isset($_GET['delivery'])) {
  echo ' Delivery Charges ';
  echo "<form name= 'instal' action ='' method='GET'>";
  echo "<input type='decimal'  name='total' size='10' >";
  echo "<input type='decimal'  name='ins_gst' size='2' value='' >";
  echo "<input type='submit' name='submit' value='Submit' >";
  echo "</form>";
  $total=$_GET['total'];
  $gst=$_GET['ins_gst'];
  echo $total;
  // Update to mysql.....
  } else {
    $total=0;
    $gst=0;
  // Update to mysql ....
  }
  if(isset($_GET['discount'])) {
    echo 'Discount Percentage';
    echo "<form name= 'instal' action ='' method='GET'>";
        echo "<input type='decimal'  name='ins_gst' size='2' value='' >";
    echo "<input type='submit' name='submit' value='Submit' >";
    echo "</form>";
    $total=$_GET['total'];
    $gst=$_GET['ins_gst'];
    echo $total;
    } else {
    $total=0;
    $gst=0;
    // Update to mysql ....
    }
?>