Hello,
I can spot (at least) two mistakes in your code:
if($result = false) is an assignation; $result will always be assigned the value "false" here. It should be a comparison instead (with the == operator).
echo "<table border='1'>
<tr><th>Nom_Variable</th>
<th>Valeur</th></tr>;
The " quote is opened but never closed.
Also, why are you writing in English? This forum is mostly french speaking (although it appears that there is an automated translation feature that activates itself in some cases).