Random time delay

I'm trying to send signals between processes and I need to allow a random time delay of between 0.01 and 0.1 seconds in my signal generation loop. So this is what I'm doing and it is most certainly not between 0.01 and 0.1, but comes out as 1 second. Not sure what I'm missing here.

    sleepTime = 100000L+(long)((1e6-1e5)*rand()/(RAND_MAX+1.0));        
    usleep(sleepTime);