Locking a field in HyperCard 2.0 makes all the text in the field “HOT”: any word or words in the field can be used as a trigger for action. Three new HyperTalk functions support this feature:
clickText, which returns the text clicked
clickChunk, which returns the run of text that was clicked (i.e., chars 33 to 45 of cd fld 4)
clickLine, which returns the line that was clicked (i.e., line 5 of fld 2)