TAIPEI, TAIWAN - Planning to post an update on Facebook from office?

From now on, users might need to check out the rules of your workplace first. Nearly half of Taiwan's companies do not allow employees to visit the popular social network Facebook at work, according to a new survey released yesterday.

The poll, conducted by Yes123 online job bank, surveyed nearly 3,000 office workers and found that 50 percent of their employers forbid them from accessing Facebook at work.

Facebook has enjoyed a stunning surge in popularity among Taiwanese users, as surveyed office workers said they spend an average of 1.5 hours daily on the social networking site while on the job.

The survey also showed that MSN is the most popular social networking site among employees, as respondents said they spend an average of 2.4 hours a day on MSN.

Half of the MSN users polled said they use the system for business; while 40 percent said they use it to chat during work.

More businesses are setting clear rules to ban employees from using the social networking site or limit their access to the site in an effort to prevent the site from diverting employees' attention and affecting their work efficiency.