PHP $_POST and variables

Question

Hey Ya'll I have a question (sorry dont have code, but i'll try my best explaining) I have an input text field with a value in it....that value goes into a variable...

$amount = $_POST['amount']

So in this form if something is missing and the user gets an error message (something didn't match up or invalid information) I would like the variable $amount put back into the input text field...is this possible?

Sorry for lack of details, but I have no idea how to code this.

Thanks

• user979331: I have echoed out the variable $amount after the form gets submitted and its coming back with the right data, just need to know how to put that variable into the form.
• DaveRandom: 9 question and 0 accepts? Really? It's that little green tick icon - and people will be a lot more willing to help you if you use it more often...
• Rob W: You also have to end your line with a semicolon: $amount = $_POST['amount'];

Answer 1

Yes, you can do this:

<input type="text" size="25" value="<?php echo $amount; ?>" />

Be sure the user can't inject HTML back onto the page, as that could cause issues. Typecasting $amount to an integer might be appropriate in this case. Two solutions could be:

$amount = (int) $_POST['amount'];

$amount = htmlentities($_POST['amount']);

• drew010: Also make sure to use htmlspecialchars so bad input doesn't end up breaking the HTML, or allowing XSS or something.
• cHao: I'd recommend htmlentities($_POST['amount']) rather than just $_POST['amount'] -- keeps chars like quotes, ampersands etc from screwing with the HTML.
• Gazillion: I often work in a bilingual environment so I'd just like to add that htmlentities needs you to mention the encoding as one of its parameters if you want it to work correctly.
• user979331: this is what is already in the value number_format(htmlentities($invoiceArray[0]["remainingbalance"]),2, ".", "")
• user979331: can't I do $invoiceArray[0]["remainingbalance"] = $amount