Make pre-populated PHP form submit on page load

Question

I've got a working PHP form that I've built and it contains 5 fields which are pre-populated by a URL query string.

The query string URL is on a hyperlink on an HTML email asking the recipient to click here to make a booking. I've got their details already because I've sent them the email, hence why the form get pre-populated.

How can I get the form to instantly submit on page load and redirect to the thank you page?

Here's how my form looks at the moment:-

<form name="frm" id="frm" method="POST">

<input name="firstname" id="firstname" type="text" value="<?php echo ((isset($_GET["firstname"]))?htmlspecialchars($_GET["firstname"]):""); ?>" />

<input name="lastname" id="lastname" type="text" value="<?php echo ((isset($_GET["lastname"]))?htmlspecialchars($_GET["lastname"]):""); ?>" />

<input name="email" id="email" type="text" value="<?php echo ((isset($_GET["email"]))?htmlspecialchars($_GET["email"]):""); ?>" />

<input name="company" id="company" type="text" value="<?php echo ((isset($_GET["company"]))?htmlspecialchars($_GET["company"]):""); ?>" />

<input name="contactid" id="contactid" type="text" value="<?php echo ((isset($_GET["contactid"]))?htmlspecialchars($_GET["contactid"]):""); ?>" />


    <input type="submit" name="Submit" value="submit" />
</form>

And here's the JavaScript I've tried (but didn't work):-

window.onload = function() {
setInterval(function(){
    document.getElementById("frm").Submit();
},5000);
}

Here's a pastebin of the whole page: http://pastie.org/private/lgpealjya8xrwqi78gropw

Thanks

Answer 1

Alright so basicaly you have been trying to get information through url, insert them in a form and then submit the form so you can send an email. This is all quite nice although you're just making things harder than they are. You you need to do is wipe off the form (we don't need this really) and instead of processing all those $_POST information you wanted to get off the form, you gonna do that with the $_GET array you already got off the url, at the end of the day it's exactly the same since the informations you're inserting in the form are only the ones you're getting off the url.

So if you change this the following way, youe script will work just fine :

//Get the submitted data
$firstname = cleanText($_GET['firstname']);
$lastname = cleanText($_GET['lastname']);
$email = cleanText($_GET['email']);
$company = cleanText($_GET['company']);
$contactid = cleanText($_POST['contactid']);

So here is what's gonna happen : the user is going to clic on a link, your script is going to get the $_GET array, process it, send the email based on this array, and this send the user to the thankyou.php page. Note that you could get your script to be more efficient and save the user some time if you insert your script in the thankyou.php.

Last but not least I would like to point out to you that it's not very good practice to get an email sent on url submission... you could end up having a bot send massive amounts of emails through this url and get you email blacklisted. If I were you I'd either control the ip and make sure only 1 mail is sent every 10 minutes or whatever time suits your needs best, or i'd add a captcha to the page so the user would need to show he's a human being who actualy wants to waste some time sending email.

Answer 2

try using: document.getElementById('frm').submit(); instead of document.getElementById('frm1').submit();

and also make it execute once the page has been loaded:

window.onload=function(){
  document.getElementById('frm').submit();
}