Some of my script lines are too long and difficult to read on screen

AppleScript supports a continuation character if you want to break a line to make it more readable in the Script Editor window. To insert the continuation character, type option-return. An “L”-shaped character is inserted at the end of the line and your cursor is moved to a new line. When the script executes, it treats the second part of the line as though it is on the original line.

You can use as many continuation characters as you want to make your script readable (even several within the same line), however, you cannot insert a continuation character within a string.

if thisNumber is greater than 5 and thisNumber is less than 255 then Ã?¬
	display dialog "Hey!" with icon note buttons {"Do it again!"} Ã?¬
		default button 1 giving up after 2