Here is a sample code where in the origpage.php passed the value to targetpage_is_very_long.php. The targetpage must be rewrite to targetpage.php.

origpage.php

<?php
echo '<form method="POST" action="targetpage_is_very_long.php">';
echo '<input type="text" name="txt1" value="this is a sample">';
echo '<input type="submit" name="submit">';
echo'</form>';
?>

targetpage_is_very_long.php

<?php
if (isset($_POST['submit']))
{
	echo $_POST['txt1'];  
}

?>