How to get age in years(rounded off to nearest number) in a textbox3,suppose we are having Date of birth of a person in textbox2 and today's date in textbox1?

Something like this: almost gives you the answer. But it is only accurate after 9/9 any year. So if the date is after December 31, midnight (after New Year's), but before the birthday, you need to subtract 1.

Statements that are True or False = -1 if True, and 0 if False.

Adding a minus value subtracts the absolute value of it.

So if you [u]add</u> to the statement’s value (the purple part is pseudocode)