Otherwise , print the equation of the normal
if ( slope != - 1 && slope != - 2 ) { x1 *= - slope ; x1 += y1 ; if ( x1 > 0 ) document . write ( " " + slope + " " + x1 . toFixed ( 1 ) ) ; else document . write ( " " + slope + " " + x1 . toFixed ( 1 ) ) ; } }