The internet-robot which allows one to obtain information on the main parameters of solar activity and geomagnetic field variation via internet with a minimal traffic is developed (http://www.univer.kharkov.ua/astron/sw/swnow.html). The correlation between strength of geomagnetic field disturbance in geostationary orbit and planetary K_p-index is derived. On this basis we propose a new 15-minute index of geomagnetic field perturbation, K_P15, which is presented on our site. The internet-robot may be useful for any researchers who need operative information on space weather.