'It is very hard to make friends in this industry,' Ms Wong said. 'Everyone, including people at your branch, are your competitors, and the competition is so keen. In the past 17 years I only made one true friend. And I guess the reason why we are still friends is that we have never worked in the same area.'

A property agent's monthly result, as with any industry based on making sales, determines everything. 'It affects that month's income, how the bosses talk to you, how many friends you have at work, whether you can be promoted and whether you can keep your job,' Ms Wong said.

'The bosses do not really care how you get the deal done. They don't care how dirty things get as long as you earned enough for the company and no one complains,' she said. 'The money you earn directly equals your value in the company. Nothing else is considered.'

Ms Wong said Centaline expected staff to produce good results and be highly aggressive, but compared with other agencies it retained a relatively higher integrity.

'At least we don't swear in front of our competitors and we never hit them. I've seen too much of it. Sometimes we pretend that we don't hear their swear words. Sometimes we fight back, in a more refined way. The competition is there. You can't avoid it. You have to be strong.

'When I was a junior a deal was almost closed, but the client refused to come down to sign the contract,' Ms Wong said. 'I asked my supervisor to help. She refused. I was so angry and thought she was not helpful. I went up to the client's flat. I rang the bell, the client opened the door and I saw an agent of another company about to sign the contract with the client. The agent wanted to close me out of the flat. I yelled through the door that I could give the client a better deal. At that time, I didn't even know what the rival's deal was. I was just trying my luck. Finally I got the deal. The competitor watched us sign the contract. I was so happy, that I was no longer angry with my supervisor.'

But there have been high points. Ms Wong worked on a new property project in 2003. The branch was aiming for the award for making more than HK$10 million a year.

One of Ms Wong's staff called her while she was out of the office to say her colleagues had made several deals on their own. 'I was so happy I cried on the spot. I still remember that day - October 6.'

The line between being strong and going too far is hard to draw. When Ms Wong was first in charge of a branch she tried to be a strong manager but was too harsh. Many of her staff left because they could not stand her attitude.

'It was not good for the branch. Team spirit is important to boost sales results,' she said.

She learnt to mix being strict with being nice, but sometimes that is not possible. 'If staff cannot make HK$30,000 in three months they have to go. Rules are rules and they are created to be followed.' Ms Wong's success was rewarded in 2005 when she was recognised as one of the top 20 sales managers in the industry and she may do well again this year.

But she has paid the price. 'I don't want to be single but there's nothing much I can do about it. I told myself I'll find someone when the time comes. But I've been waiting all these years and I still have no idea when the time will come. I had dinner with our chairman Shih Wing-ching some months ago. I said to him: 'I sold all my youth to you', which is true.'