State Change in User Defined Function

stateChange() {
    if (TRUE)
        state foo;
}

default {
            state_entry()
            {

             llSay(0,"I'm in state default! Touch me to go to state foo.");

            }

            touch_end(integer num)
            {
                stateChange();
            }
}

state foo {
             state_entry()
            {

             llSay(0,"I'm in state foo! Touch me to go bac to state default.");

            }


            touch_end(integer num)
            {
                state default;
            }
}