I tried looking online for all possible solutions and even installing evtouch package, but nothing seems to work. I know that the tx1000 series laptops are notoriously linux unfriendly. Does anyone have any ideas on how to get the touchscreen to work on them?
It uses a proprietary driver called eGalax. It's not available or supported in Ubuntu but here's a link to the driver download: http://home.eeti.com.tw/web20/eGalaxTouchDriver/linuxDriver.htm
Ideally, the Linux kernel's general purpose evdev input driver should make the touchscreen "just work", however its support for touchscreen models is far, far from complete. If you're really interested in getting it working and don't mind getting your hands dirty into some source code, you might be able to lend a hand to the evdev kernel developers to make it work for this hardware (or they might have some configurable settings you could try.)
I wouldn't bother with evtouch for this hardware; it's not at all maintained and is being deprecated in favor of evdev.