Hi, Michael

Block Comment

Adds the comment character to each line of a selected block of text. If multiple lines are not selected, a single comment is added to the start of the line containing the cursor.

Block Uncomment

Removes the comment character from each line of a selected block of text. If multiple lines are not selected, a single comment is removed from the start of the line containing the cursor
In the toolbar ... the green/blue and green/green lines

just on the left side of the " compile only " button ...

Alain