HTML Form Value returning null in PHP script? (basic question)

[Jakesta42]

Hello,

 

I'm trying to take the value from an HTML form and insert it into a database on a button click. It inserts a null value into the database. The script is called submitColumnDetails.php.

 

 

This is where I create the text field that I want to take the information from. This is in a separate file.

echo <<<END
<form action = "submitColumnDetails.php" method = "POST">
<input type = "text" name = "columnField"/>
</form>
END;

 

This is the submitColumnDetails.php file

 

<?php
//Submit Column Data
//-----------------------------------------------------//
//Connect to localhost server
$connector = mysql_connect("localhost", "root", "root");
if(!$connector){	//If user can't connect to database
die('Could not connect: ' . mysql_error()); //Throw an error
}			
//-----------------------------------------------------//

mysql_select_db("colin_db", $connector);

$newValue = $_POST["columnField"];	//Data from column field. THIS IS WHAT RETURNS NULL
$newColumnQuery = "INSERT INTO `colin_db`.`allColumnFields` (`DATA`) VALUES ('$newValue')";
mysql_query($newColumnQuery); //Query to add form to main table

$newColumnIntoMainTableQuery = "ALTER TABLE colin_table ADD ('$newValue' varchar(50))";
mysql_query($newColumnIntoMainTableQuery);	//Query to add column to main table


mysql_close($connector);	//Close database connection
echo "<script type = 'text/javascript'> window.location = 'index.php'</script>";
//Go back to original page
?>			

 

Even when I print out the $newValue, it does not print anything. What am I doing incorrectly?