TSL functions

1.What are the TSL functions available when working with Winrunner?

I. tddb_ get_ step_ value
II. tddb_ get_ test_ value
III. tddb_get_testset_value
IV. tddb_ get_ teststep_ value

2.Which sign indicates that all Text from this point to the end of the line is a comment?
After saving a test in WinRunner 6.02, you may not be able to open it later with previous versions of WinRunner. What can be done to solve this issue?

Remove the log file from the test folder.

Remove script file from the test folder.
Remove ddt_func from dat file.