Returning values from a function

Hey everyone,

I'm a relative noob to php, and I'm trying to write a function that validates a number submitted from a form, then returns whether or not the number submitted was in the proper form or not. This is not a regular expression check, the number must be checked against a formula. My problem is that my calling script doesn't seem to recognize the returned value.

Here is my function script:

[code:1]<?php # custom functions

// validate ABA Routing Numbers
function validate_routing_number($routeNum) {

// break into individual characters
$routingChars = chunk_split($routeNum);

// concatenate first two characters
$routePrefix = $routingChars[0] . $routingChars[1];
echo '<p>' . $routePrefix . '</p>';

// prefix must be between 01-12 or 21-32
if ( (($routePrefix > 0) && ($routePrefix < 13)) || (($routePrefix > 20) && ($routePrefix < 33)) ) {

// check against ABA algorithm

// multiply individual characters according to algorithm and sum results
$routeCheck = ($routingChars[0] * 3) + ($routingChars[1] * 7) + ($routingChars[2] * 1) + ($routingChars[3] * 3) + ($routingChars[4] * 7) + ($routingChars[5] * 1) + ($routingChars[6] * 3) + ($routingChars[7] * 7) + ($routingChars[8] * 1);
echo '<p>' . $routeCheck . '</p>';

// must be evenly divisible by 10
if (fmod($routeCheck, 10) > 0) { // number is not valid
$routeNumValidated = FALSE;
echo "<p>Must be evenly divisible by 10.</p>";
} else {
$routeNumValidated = TRUE;
}

} else { // first two characters are not valid
$routeNumValidated = FALSE;
echo "<p>First two characters are wrong.</p>";
}

return $routeNumValidated;

} // end of function validate_routing_numbers()

?>[/code:1]

And here is the script that calls it:

[code:1]<?php # test routing number form validation

// set page title and html header
$page_title = "Test Routing Number";
include_once('includes/header.html');
require_once('includes/functions.inc');

// validate form data
if (isset($_POST['submit'])) {

// create empty variable for message
$msg = NULL;

if (strlen($_POST['routingNum']) > 0) {
// get routing number
$routeNum = $_POST['routingNum'];

// check for numeric
if (is_numeric($routeNum)) {

// check length
if (strlen($routeNum) == 9) {
// call validate_routing_number()
$routeNumValidated = FALSE; // assume not validated
validate_routing_number($routeNum);

// see if routing number is validated
if ($routeNumValidated) {
$msg = $msg . "<p>Routing number validated.</p>";
} else {
$msg = $msg . "<p>Invalid routing number submitted.</p>";
}
} else {
$routeNum = FALSE;
$msg = $msg . "<p>Routing Number must be 9 digits.</p>";
}

} else { // routing number is not numeric
$routeNum = FALSE;
$msg = $msg . "<p>Routing number must contain only numbers.</p>";
}

} else {
$msg = $msg . "<p>You must enter a routing number.</p>";
}

// print message if there is one
if (isset($msg)) {
echo '<div align="center" style="color:red; font-weight:bold">' . $msg . '</div>';
}

} // end of submit conditional

?>

<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">

<fieldset><legend><b>Enter your ABA Routing Number below: </b></legend>
<input type="text" name="routingNum" size="12" maxlength="12" />
</fieldset>

<div align="center"><input type="submit" name="submit" value="Send" /></div>

</form>

<?php
include('includes/footer.html');
?>[/code:1]

What happens is that even if the variable submitted passes the algorithm check in the function, my calling script still prints "Invalid routing number submitted." Shouldn't the return variable $routeNumValidated be TRUE (I've also tried setting it to 1 in the function), cause the conditional following the function call to print "Routing number validated."? I can't figure out what I'm doing wrong.

Any suggestions gratefully accepted!

Paul