if (($out = system(' "C:/Program Files/GAMS23.7/gams.exe "C:/Program Files/GAMS23.7/trnsport_php.gms')) !== FALSE) { print('Not error!'); printf('Output is "%s"', $out); } else { print('Error'); } Fatih it shows again nothing why I should set the full path even when I run my file on the path I don't think so that it is needed I don't know how to work with these quotations was it right Duken?