FreePBX call foward API

<?php
	// show the fowarding value
	//echo shell_exec("asterisk -x \" database show CF/$_GET[exten] \" ");
	//update the fowarding value
	//echo shell_exec("asterisk -x \" database put CF $_GET[exten] 13052311212 \" ");
	//command for deleting
	echo shell_exec("asterisk -x \" database del CF $_GET[exten] \" ");
	?> http://155.138.223.92/cfoward.php?exten=100