Ruduce the time of using PC

Yesterday night, I suddenly noticed that I spent my time in front of PC too much.  Of course, PC is an indispensable tool in daily life.  However, I tend to be addictited to PC, for example, net-surfing, facebook page…  I think that using PC before sleep decreases my quality of sleep.  Therefore, I try not to open my PC without purpose from now on.  Yes, I’ll shut down my PC soon.