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  • #44869

    I am trying to validate a form and I keep getting an error: Notice: Undefined variable: errorString in C:xampphtdocsintroducingphpemailrequired_fieldsindex.php on line 7

    The form fields also fill with error text. The form works fine

    <title>PHP Form Processing Example</title>

    <?php echo $errorString; ?>

    <form action="process.php" method="POST">
    Name:*<br /><input type="text" name="Name" value="<?php echo $Name; ?>" /><br /><br />
    Email:*<br /><input type="text" name="Email" value="<?php echo $Email; ?>" /><br /><br />
    URL:*<br /><input type="text" name="URL" value="<?php echo $URL; ?>" /><br /><br />
    Company:<br /><input type="text" name="Company" value="<?php echo $Company; ?>" /><br /><br />
    <input type="submit" name="submit" value="Submit Form" />

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    This is the process.php

    * Specify the field names that are in the form. This is meant
    * for security so that someone can't send whatever they want
    * to the form.
    $allowedFields = array(

    // Specify the field names that you want to require...
    $requiredFields = array(

    $errors = array();
    foreach($_POST AS $key => $value)
    // first need to make sure this is an allowed field
    if(in_array($key, $allowedFields))
    $$key = $value;

    // is this a required field?
    if(in_array($key, $requiredFields) && $value == '')
    $errors[] = "The field $key is required.";

    // were there any errors?
    if(count($errors) > 0)
    $errorString = '<p>There was an error processing the form.</p>';
    $errorString .= '<ul>';
    foreach($errors as $error)
    $errorString .= "<li>$error</li>";
    $errorString .= '</ul>';

    // display the previous form
    include 'index.php';
    // At this point you can send out an email or do whatever you want
    // with the data...

    // each allowed form field name is now a php variable that you can access

    // display the thank you page
    header("Location: thanks.html");

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    you need to check if the variable is initialize i.e

    if(!isset $errorString){
    //stuff to do if $errorString is not set
    echo $errorString;

    As for the form fields add something like

    !empty($Name) ? echo $Name : echo ”;

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