I am trying to connect to wifi using wpa_cli set_network command,but it always returns FAIL

krishna@krishna-PC:~/Downloads/wificonnect1$ sudo wpa_cli scan [sudo] password for krishna: Selected interface 'wlan0' OK krishna@krishna-PC:~/Downloads/wificonnect1$ sudo wpa_cli scan_results Selected interface 'wlan0' bssid / frequency / signal level / flags / ssid fc:0a:81:1d:6d:80 2412 -43 [WPA2-PSK-CCMP][ESS] econsys 00:24:01:ba:b4:65 2437 -72 [WPA-PSK-TKIP][WPA2-PSK-TKIP][WPS][ESS] Test 6c:72:20:f2:1a:6b 2412 -60 [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS] Hari c0:ee:fb:31:ec:4a 2447 -76 [WPA2-PSK-CCMP][ESS] Vishal's hotspot fc:0a:81:1c:6d:f0 2412 -61 [WPA2-PSK-CCMP][ESS] econsys c4:12:f5:08:10:70 2427 -63 [WPA-PSK-CCMP][WPA2-PSK-CCMP][ESS] GoGreen f4:f2:6d:6d:23:44 2462 -62 [WPS][ESS] joyglobal krishna@krishna-PC:~/Downloads/wificonnect1$ sudo wpa_cli add_network Selected interface 'wlan0' 1 krishna@krishna-PC:~/Downloads/wificonnect1$ sudo wpa_cli set_network 1 ssid "econsys" Selected interface 'wlan0' FAIL How should I connect?