<?php

$host = "https://abc.com";
$client = new SoapClient("https://abc.com/api/v2_soap/?wsdl");
$apiuser= "bala"; 
$apikey = "bala123";
$action = "sales_order.list"; 
try {

$sess_id= $client->login($apiuser, $apikey); 

print_r($client->call($sess_id, $action));
}
catch (Exception $e) { //while an error has occured
echo "==> Error: ".$e->getMessage(); //we print this
exit();
}

?>