Question

Form by example.

$fullname = 'John Travolta';

<input type="text" name="fullname" />
<input name="same" type="checkbox" /> Tick if same name

1. When we tick on the checkbox the input fullname will insert automatically by data from $fullname
2. How to do that by javascript, jquery or etc ?

Answer 1

You should use javascript (or JQuery, which is a javascript library) to do this, but since $fullname is probably a PHP variable you will need to use that too.

A simple javascript example (which can probably done a bit neater with JQuery) that uses the php variable:

<input id="fullname" type="text" name="fullname" />
<input id="same" name="same" type="checkbox" 
   onchange="javascript:samename('<?php echo htmlspecialchars($fullname) ?>')" />

this calls a javascript function that should look something like

function samename(fullname) {
  same = document.getElementById('same');
  full = document.getElementById('fullname');
  if(same.checked) {
    full.value = fullname;
  } else {
    full.value = '';
  }
}