You don't need javascript for doing so. Just delete the onClick and write the php Admin.php file like this:
<!-- HTML STARTS-->
<?php
//If all the required fields are filled
if (!empty($GET_['fullname'])&&!empty($GET_['email'])&&!empty($GET_['name']))
{
function addNewContact()
{
$new = '{';
$new .= '"fullname":"' . $_GET['fullname'] . '",';
$new .= '"email":"' . $_GET['email'] . '",';
$new .= '"phone":"' . $_GET['phone'] . '",';
$new .= '}';
return $new;
}
function saveContact()
{
$datafile = fopen ("data/data.json", "a+");
if(!$datafile){
echo "<script>alert('Data not existed!')</script>";
}
else{
$contact_list = $contact_list . addNewContact();
file_put_contents("data/data.json", $contact_list);
}
fclose($datafile);
}
// Call the function saveContact()
saveContact();
echo "Thank you for joining us";
}
else //If the form is not submited or not all the required fields are filled
{ ?>
<form>
<fieldset>
<legend>Add New Contact</legend>
<input type="text" name="fullname" placeholder="First name and last name" required /> <br />
<input type="email" name="email" placeholder="[email protected]" required /> <br />
<input type="text" name="phone" placeholder="Personal phone number: mobile, home phone etc." required /> <br />
<input type="submit" name="submit" class="button" value="Add Contact"/>
<input type="button" name="cancel" class="button" value="Reset" />
</fieldset>
</form>
<?php }
?>
<!-- HTML ENDS -->
Thought I don't like the PHP bit. Do you REALLY want to create a file for contacts? It'd be MUCH better to use a mysql database. Also, adding some breaks to that file would be nice too...
Other thought, IE doesn't support placeholder.