Raspberry pi setup wifi static IP

This is how I setup wifi on my PI :

In /etc/network/interfaces

auto lo

    iface lo inet loopback
    iface eth0 inet static
    address 10.232.1.81
    netmask 255.255.255.0
    gateway 10.232.1.1


    auto wlan0
    allow-hotplug wlan0
    iface wlan0 inet static
    address 10.232.1.99
    netmask 255.255.255.0
    gateway 10.232.1.1
    wpa-passphrase password
    wpa-ssid myssid

I have tried everything using /etc/wpa_supplicant/wpa_supplicant.conf, it never works !!!