write(*,*)'input x=?'
	  READ(*,*) X
c40      FORMAT(F8.2)
        IF(X)10,20,30
10	    Y=-1.57079
        GOTO 100
20	    Y=0
        GOTO 100
30	    Y=1.57079
        GOTO 100
100	  WRITE(*,50)X,Y
50	  FORMAT(1X,2HX=,F10.6,4H Y=,F10.6)
        END