100 OPTION ANGLE DEGREES
110 DEF f(x)=tan(x)
120 SET WINDOW -100,500,-5,5
130 DRAW GRID(90,1)
140 SET POINT STYLE 1
150 FOR x=-100 TO 500 
160    WHEN EXCEPTION IN  
170       PLOT LINES: x,f(x);
180    USE
190       PLOT LINES
200    END WHEN
210 NEXT x
220 END
