Netvudu, the simplest way of sequencing legato is to save a copy of your flute and slow the attack by 0.1 - 0.2 sec. Cut and paste the legato notes on to a second track and overlap them slightly with the preceding notes. Make sure the releases of both instruments are long enough -at least 0.15 sec. Experiment with different attacks, until you get the transition you want. (You can use \"sample offset\" to remove the original tonguing completely, but you\'ll need a slower attack).
Bear in mind that the legato transition in real flute playing is infinitely variable between definite tongeing from the palate (a tongued \"d\" with the tip curled slightly away from the teeth) and true slur with no tonguing. Even in true slurring there is a brief transition sound as one standing wave breaks down and the next one builds up, giving a soft, minisculy transient \"L\" sound. So don\'t bother to try and create a radically smooth transition. I don\'t believe there is any portamento across the transition, unlike in a stringed instrument.