[PHP] display a hiddenfield

[Dominique ANOKRE]

I use a simple form like this : 

print("<form method=\"post\" action=\"image.php\">\n");
print("<input type=\"hidden\" name=\"hiddenField\">\n");
$_POST["hiddenField"] = $image_avant;
print("<input type=\"submit\" name=\"avant\" value=\"Avant\">\n");
print("</form>\n");

and when i click on the submit button, i want to display the value of my hiddenField 
(doing by the file image.php) :

 <?php
echo $_POST["hiddenField"];
?>

but nothing is displaying !!!!!!

Please help !