Something

if(isset($_POST['deltagare']) )
	{
		//Ta bort avklickade namn
		foreach($_POST['deltagare'] as $val)
		{
			echo $val;
			if( $val == false )
			{
				echo "false";
			}
			else
			{
				echo "halo";
			}
		}
	}
	echo "ok";

//When all checkboxes is unchecked, this outputs "ok"