Function DeFog(xvalue:Int , yvalue:Int)
    Local radius:Int = 3, dist:Int = 0
    For Local y:Int = -(radius+2) To (radius+2)
        For Local x:Int = -(radius+2) To (radius+2)
            dist=Sqr( (xvalue-xvalue+x)^2 + (yvalue-yvalue+y)^2 ) - 0.25
            If dist < 0 Then dist = 0
            If dist < radius And LineOfSight(xvalue,yvalue,xvalue+x,yvalue+y) = True
                For Local xx:Int = -1 To 1
                    For Local yy:Int = -1 To 1
                        If CheckWorld(x+xvalue,y+yvalue) = False
                        '   If fow[xx+xvalue + x,yy+yvalue + y] = 0 Then MakeThing(effect_defog,xx+xvalue + x , yy+yvalue + y)
                            fow[xvalue + x ,yvalue + y] = 1
                        Else
                            If fow[xvalue + x,yvalue + y] = 0 Then MakeThing(effect_defog,xvalue + x , yvalue + y)
                            fow[xvalue + x ,yvalue + y] = 1
                        EndIf

                    Next
                Next
            EndIf
        Next
    Next
End Function