Undefined Index - CGI vs ISAPI - php

Question

See Update Below Original Question:
I am having trouble with my contact forms. I am fairly new to PHP but they have been working up to just recently when an unrelated problem required my host...CBeyond :( ... to switch from ISAPI back to CGI. Knowing that this is not as flexible (up to date) of a technology, I am more familiar with this technology so I am ok with it.
The problem began after the switch with my contact forms all showing "Undefined index" errors.
I have all my code on the same page (form, processing, validation, thankyou) and am pulling my hair out trying to figure out the problem. I am sure there are some suggestions for additional validation, etc. but for now...I just need this form to work.
One of the forms: www.faa-air.com/contact/php/mailer.php submits correctly but has the garble of text at the bottom of the page.
The other form: www.faa-air.com/contact/php/consultmailer.php does not submit correctly. It sends the result of the form but it is blank and the webpage still has all the garble at the bottom.
Below is the code for the one that is not working (consultmailer.php) but both were developed from each other so they should be logically identical ... so not sure what went wrong.
Any ideas?
<?php
if (empty($_POST['Submit'])) :
include 'phpconsultform.php'
?>
<?php
endif;
//FORM VALIDATION AND PROCESSING
$arrErrors = array();
if (!empty($_POST['Submit']))
{
if ($_POST['f_name'] == '')
$arrErrors['f_name'] = 'Your First Name is a Required.';
if ($_POST['l_name'] == '')
$arrErrors['l_name'] = 'Your Last Name is a Required.';
if ($_POST['contactemail'] == '')
$arrErrors['contactemail'] = 'A Valid Email Address is Required.';
if ($_POST['contactphone'] == '')
$arrErrors['contactphone'] = 'A Valid Phone Address is Required.';
//else if (filter_var('emailaddress', FILTER_VALIDATE_EMAIL) === FALSE)
// $arrErrors['emailaddress'] = 'Check the format of your email.';
if (count($arrErrors) == 0)
{
//FORM PROCESSING AFTER VALIDATION
$f_name = $_GET['f_name'];
$l_name = $_GET['l_name'];
$email = $_GET['contactemail'];
$phone = $_GET['contactphone'];
$phone2 = $_GET['contactotherphone'];
$avail = $_GET['availability'];
$time = $_GET['timeday'];
$freq = $_GET['frequency'];
$cert = $_GET['current_cert'];
$rate = $_GET['current_rate'];
$need1 = $_GET['cert_need'];
$need2 = $_GET['rate_need'];
$TT = $_GET['TT'];
$XT = $_GET['XT'];
$COMPLX = $_GET['COMPLX'];
$IFRT = $_GET['IFRT'];
$PICT = $_GET['PICT'];
$NGT = $_GET['NGT'];
$refer = $_GET['contactrefer'] ;
$comments = $_GET['contactcomments'] ;
$message .= 'The following request was submitted by ' .$f_name. ' ' .$l_name. "\n\n";
//$message .= 'Please respond within 1 business day' "\n\n";
$message .= 'Name: ' .$f_name. ' ' .$l_name. "\n";
$message .= 'Email: ' .$email. "\n";
$message .= 'Phone Number: ' .$phone. "\n";
$message .= 'Other Phone: ' .$phone2. "\n\n";
$message .= 'Availability: ' ;
{
foreach($avail as $value)
{
$message .= trim(stripslashes($value)) . "\n";
}
}
$message .= 'Time of Day: ' ;
{
foreach($time as $value_2)
{
$message .= trim(stripslashes($value_2)) . "\n";
}
}
$message .= 'Frequency: ' ;
{
foreach($freq as $value_3)
{
$message .= trim(stripslashes($value_3)) . "\n";
}
}
$message .= "\n\n";
$message .= 'Certifications Held: ' ;
$message .= "\n\n";
{
foreach($cert as $value_4)
{
$message .= "-- " . trim(stripslashes($value_4)) . "\n";
}
}
$message .= "\n\n";
$message .= 'Rating Held: ' ;
$message .= "\n\n";
{
foreach($rate as $value_5)
{
$message .= "-- " . trim(stripslashes($value_5)) . "\n";
}
}
$message .= "\n\n";
$message .= 'Certificates Needed: ';
$message .= "\n\n";
{
foreach($need1 as $value_6)
{
$message .= "-- " . trim(stripslashes($value_6)) . "\n";
}
}
$message .= "\n\n";
$message .= 'Ratings Needed: ';
$message .= "\n\n";
{
foreach($need2 as $value_7)
{
$message .= "-- " . trim(stripslashes($value_7)) . "\n";
}
}
$message .= "\n\n";
$message .= 'Current Logbook Times' . "\n" ;
$message .= 'Total Time: ' .$TT. "\n";
$message .= 'Cross Country Time: ' .$XT. "\n";
$message .= 'Complex Time: ' .$COMPLX. "\n";
$message .= 'IFR Time: ' .$IFRT. "\n";
$message .= 'PIC Time: ' .$PICT. "\n";
$message .= 'Night Time: ' .$NGT. "\n\n";
$message .= "\n\n" ;
$message .= 'Refer: ' .$refer. "\n\n";
$message .= 'Comments: ' .$comments ;
$message .= "\n\n" ;
$message .= "\n\n" ;
$message .= "\n\n" ;
mail ( "you#knowwho.com", " Custom Consult Inquiry", $message, $email) ;
//DISPLAY THANK YOU PAGE
include 'thankyou.php';
}
else
{
$displayError = '<div align="center"><ul>';
foreach ($arrErrors as $error)
{
$displayError .="<li><b>$error</b></li>";
}
$displayError .= '</div></ul>';
//DISPLAY FORM WITH ERRORS
include 'phpconsultform.php'
?>
<?php
}
}
?>
UPDATE
I was able to get the form to send correctly but changed,
$f_name = $_GET['f_name'] ;
to
$f_name = $_REQUEST['f_name'] ;
I am sure there are some issues (again I am new) but it works.
I am still getting the E_NOTICE errors that I can't understand. I like the E_NOTICE so if I miss a colon or something I can easily find it however nothing I do helps. I appreciate the advise and hope I can get one more response on my error notices.

Answer 1

All that's changed is your error reporting level. It now includes E_NOTICE.
You need to check for array indexes and variables before using them. For example, instead of...
if ($_POST['f_name'] == '')
use
if (empty($_POST['f_name']))
this is because empty is safe to use on potentially undefined variables / indexes.
Another one, this...
$f_name = $_GET['f_name'];
is safe as
$f_name = isset($_GET['f_name']) ? $_GET['f_name'] : null; // or whatever you want to use as a default value.
Finally, you should assign an initial value to your $message string before using it with the concatenation operator (.=), eg
// as this is the first appearance of $message, just assign the initial value directly
$message = 'The following request was submitted by ' .$f_name. ' ' .$l_name. "\n\n";