<h2>Calculator</h2>
<form method="post" action="index.php">
    <table>
        <tr>
            <th><label for="name"> Name </label></th>
            <td><input type="text" id="name" name="name" value="<?php if( isset($name) ){ echo $name; } ?>" /></td>
        </tr>
        <tr>
            <th><label for="email"> Email </label></th>
            <td><input type="text" id="email" name="email" value="<?php if( isset($email) ){ echo $email; } ?>"/></td>
        </tr>
        <tr>
            <th><label for="state"> State </label></th>
            <td>
              <select id="state" name="state">
                <option value="AL"<?php if( isset($state) && $state == "AL" ){ echo " selected"; } ?>>Alabama</option>
                <option value="AK"<?php if( isset($state) && $state == "AK" ){ echo " selected"; } ?>>Alaska</option>
                <option value="AZ"<?php if( isset($state) && $state == "AZ" ){ echo " selected"; } ?>>Arizona</option>
                <option value="AR"<?php if( isset($state) && $state == "AR" ){ echo " selected"; } ?>>Arkansas</option>
                <option value="CA"<?php if( isset($state) && $state == "CA" ){ echo " selected"; } ?>>California</option>
                <option value="CO"<?php if( isset($state) && $state == "CO" ){ echo " selected"; } ?>>Colorado</option>
                <option value="CT"<?php if( isset($state) && $state == "CT" ){ echo " selected"; } ?>>Connecticut</option>
                <option value="DE"<?php if( isset($state) && $state == "DE" ){ echo " selected"; } ?>>Delaware</option>
                <option value="DC"<?php if( isset($state) && $state == "DC" ){ echo " selected"; } ?>>District Of Columbia</option>
                <option value="FL"<?php if( isset($state) && $state == "FL" ){ echo " selected"; } ?>>Florida</option>
                <option value="GA"<?php if( isset($state) && $state == "GA" ){ echo " selected"; } ?>>Georgia</option>
                <option value="HI"<?php if( isset($state) && $state == "HI" ){ echo " selected"; } ?>>Hawaii</option>
                <option value="ID"<?php if( isset($state) && $state == "ID" ){ echo " selected"; } ?>>Idaho</option>
                <option value="IL"<?php if( isset($state) && $state == "IL" ){ echo " selected"; } ?>>Illinois</option>
                <option value="IN"<?php if( isset($state) && $state == "IN" ){ echo " selected"; } ?>>Indiana</option>
                <option value="IA"<?php if( isset($state) && $state == "IA" ){ echo " selected"; } ?>>Iowa</option>
                <option value="KS"<?php if( isset($state) && $state == "KS" ){ echo " selected"; } ?>>Kansas</option>
                <option value="KY"<?php if( isset($state) && $state == "KY" ){ echo " selected"; } ?>>Kentucky</option>
                <option value="LA"<?php if( isset($state) && $state == "LA" ){ echo " selected"; } ?>>Louisiana</option>
                <option value="ME"<?php if( isset($state) && $state == "ME" ){ echo " selected"; } ?>>Maine</option>
                <option value="MD"<?php if( isset($state) && $state == "MD" ){ echo " selected"; } ?>>Maryland</option>
                <option value="MA"<?php if( isset($state) && $state == "MA" ){ echo " selected"; } ?>>Massachusetts</option>
                <option value="MI"<?php if( isset($state) && $state == "MI" ){ echo " selected"; } ?>>Michigan</option>
                <option value="MN"<?php if( isset($state) && $state == "MN" ){ echo " selected"; } ?>>Minnesota</option>
                <option value="MS"<?php if( isset($state) && $state == "MS" ){ echo " selected"; } ?>>Mississippi</option>
                <option value="MO"<?php if( isset($state) && $state == "MO" ){ echo " selected"; } ?>>Missouri</option>
                <option value="MT"<?php if( isset($state) && $state == "MT" ){ echo " selected"; } ?>>Montana</option>
                <option value="NE"<?php if( isset($state) && $state == "NE" ){ echo " selected"; } ?>>Nebraska</option>
                <option value="NV"<?php if( isset($state) && $state == "NV" ){ echo " selected"; } ?>>Nevada</option>
                <option value="NH"<?php if( isset($state) && $state == "NH" ){ echo " selected"; } ?>>New Hampshire</option>
                <option value="NJ"<?php if( isset($state) && $state == "NJ" ){ echo " selected"; } ?>>New Jersey</option>
                <option value="NM"<?php if( isset($state) && $state == "NM" ){ echo " selected"; } ?>>New Mexico</option>
                <option value="NY"<?php if( isset($state) && $state == "NY" ){ echo " selected"; } ?>>New York</option>
                <option value="NC"<?php if( isset($state) && $state == "NC" ){ echo " selected"; } ?>>North Carolina</option>
                <option value="ND"<?php if( isset($state) && $state == "ND" ){ echo " selected"; } ?>>North Dakota</option>
                <option value="OH"<?php if( isset($state) && $state == "OH" ){ echo " selected"; } ?>>Ohio</option>
                <option value="OK"<?php if( isset($state) && $state == "OK" ){ echo " selected"; } ?>>Oklahoma</option>
                <option value="OR"<?php if( isset($state) && $state == "OR" ){ echo " selected"; } ?>>Oregon</option>
                <option value="PA"<?php if( isset($state) && $state == "PA" ){ echo " selected"; } ?>>Pennsylvania</option>
                <option value="RI"<?php if( isset($state) && $state == "RI" ){ echo " selected"; } ?>>Rhode Island</option>
                <option value="SC"<?php if( isset($state) && $state == "SC" ){ echo " selected"; } ?>>South Carolina</option>
                <option value="SD"<?php if( isset($state) && $state == "SD" ){ echo " selected"; } ?>>South Dakota</option>
                <option value="TN"<?php if( isset($state) && $state == "TN" ){ echo " selected"; } ?>>Tennessee</option>
                <option value="TX"<?php if( isset($state) && $state == "TX" ){ echo " selected"; } ?>>Texas</option>
                <option value="UT"<?php if( isset($state) && $state == "UT" ){ echo " selected"; } ?>>Utah</option>
                <option value="VT"<?php if( isset($state) && $state == "VT" ){ echo " selected"; } ?>>Vermont</option>
                <option value="VA"<?php if( isset($state) && $state == "VA" ){ echo " selected"; } ?>>Virginia</option>
                <option value="WA"<?php if( isset($state) && $state == "WA" ){ echo " selected"; } ?>>Washington</option>
                <option value="WV"<?php if( isset($state) && $state == "WV" ){ echo " selected"; } ?>>West Virginia</option>
                <option value="WI"<?php if( isset($state) && $state == "WI" ){ echo " selected"; } ?>>Wisconsin</option>
                <option value="WY"<?php if( isset($state) && $state == "WY" ){ echo " selected"; } ?>>Wyoming</option>
              </select>
            </td>
        </tr>
        <tr style="display: none;">
            <th><label for="details"></label></th>
            <td><input type="text" id="details" name="details" />
              <p>Please leave this field blank.</p>
            </td>
        </tr>
    </table>
    <input type="submit" value="Send" />
</form>

if($_SERVER['REQUEST_METHOD'] == "POST"){
  //variables to be used from each form field's input.
  $name = trim( filter_input( INPUT_POST, "name", FILTER_SANITIZE_STRING ) );
  $email = trim( filter_input( INPUT_POST, "email", FILTER_SANITIZE_EMAIL ) );
  $state = trim( filter_input( INPUT_POST, "state", FILTER_SANITIZE_STRING ) );

  //Blank fields cannot be submitted.
  if($name == "" || $email == "" || $state == ""){
    $error_message = 'Please fill in the required fields (Name, Email, State)';
  }

$servername = "localhost";
    $username = "root";
    $password = "";
    $dbname = "calculations";

    try {
        $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
        // set the PDO error mode to exception
        $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

        // prepare sql and bind parameters
        $stmt = $conn->prepare("INSERT INTO people (name, email, state) VALUES (:name, :email, :state)");
        $stmt->bindParam(':name', $name);
        $stmt->bindParam(':email', $email);
        $stmt->bindParam(':state', $state);
        $stmt->execute();
        }
    catch(PDOException $e)
        {
        echo "Error: " . $e->getMessage();
        }
    $conn = null;