ABS and handbrake blinking warnings

Hello guys,

I have a VW POLO (year 98).

The ABS warning light is switched on every now and then. I've taken the car to a mechanic who connected the computer car with a system and told me that there was a faulty ABS sensor. he changed the left-front sensor but the problem continued and then his system showed that the right-front sensor was faulty too. To sum up, i changed the both front sensors but 2 weeks ago the ABS light is switched on again. :(

A day ago, another problem occured while i was driving, the handbrake warning light started blinking accompannied by a warning tone. When i switch off the car it stops but it come back whenever it wants.

Can you help me please?
The most important is the ABS thing, i dont want to drive unsecurily.


Thanks in advance!

Lefter

PS. Sorry about my poor english