Hey Maaz
You have to designate the point. IE lase the target with the tgp, turn laser on,("L" flashing in hud), press TMS long, turn laser off then make the mav your soi and then "V" key long, with the mav slewed you can zoom in with a "v" key short,tms short to lock, if it doesn't lock a slight slew of the mav and tms short. Don't try to reacquire the target with the mav using the "V" long a second time tho, as you cause the tgp to lose the target. you have repeat this process to keep the target locked locked. here is an excellent vid that teaches some gr8 stuff bout the TGP,
[url=ttp://www.youtube.com/watch?v=IOZ18GNPI-c]ttp://www.youtube.com/watch?v=IOZ18GNPI-c[/url]