Phal. cornu-cervi

[Alvin]

hey~here is the photoes of the leaves of my oncidium and phalaenopsis...these photoes i just took one hour ago...can anyone tell me what is the causes of this? and what can i do for it? help me...i got quite lot of orchids and very worry about others will be infected

p/s: because these spots just appear in this morning...so the color not that dark...few days ago when it happened..it became dark brown color and even black color...and i cut off those leave already...
and the mud color spots all over the leaves is some medicine i buy from the flowerbed which they said it could help...