Why do my tomato plants come to flower but not bear fruit ?

I water them regulary and there are plenty of flowers and trusses but the flower wilts and bear no fruit. I live in a warm country and there has been no cold snaps. The plants stand at around 3 feet and have plenty of leaves. I have taken the bottom two branches away so the trusses get more goodness but still this does not solve the problem. Any advice would be great, thanks in advance.

Why do my tomato plants come to flower but not bear fruit ?
try getting a q tip and cross pollinate the flowers. May beeee the beeeees have not done it for you!
Reply:The flowers are not being pollinated.When in flower use a fine hand spray with clear water to genntly spray the blossoms. You can also tap the flower sprays to make the pollen loosen. Not all the blossoms in a spray will turn into a fruit. Some will produce a green tomato that does not mature but if four or five blossoms in a spray turn into reasonable sized tomatoes then that is reasonably successful.
Reply:cut the flowers off the plant is putting to much energy into the bloom to produce fruit