Acting Chief Executive Donald Tsang Yam-kuen couldn't suppress a smile yesterday morning as the red carpet was literally rolled out for him. Shedding the stony face he displayed on Thursday when Tung Chee-hwa announced his decision to quit, Mr Tsang beamed as he walked along the carpet and onto a stage to officiate at the opening ceremony for the police force's new $2 billion headquarters at Arsenal House in Wan Chai. He was accompanied by security chief Ambrose Lee Siu-kwong and Police Commissioner Dick Lee Ming-kwai. Among the guests lining the two sides of the carpet to welcome Mr Tsang were his younger brother and former police commissioner, Tsang Yam-pui, and Lieutenant-General Wang Jitang , commander of the PLA Hong Kong garrison. Despite seeming reluctant to comment directly on his brother's promotion, the younger Mr Tsang appeared keen to draw reporters' attention to his brother's new position. Approaching the press area before his brother arrived at 10.35am, Tsang Yam-pui said the commemorative stone to be unveiled by Donald Tsang at the ceremony originally bore Mr Tung's name. 'It took the staff little time to change it,' he said. So how did he feel about his brother's new political role? 'Don't ask me these things,' he said, but his broad smile indicated the pride he felt. At last night's press conference at the Central Government Offices, Mr Tsang looked much more serious, but still appeared the happiest person in the line of senior officials present, with all the rest wearing the gravest of expressions. Asked what he had been feeling when he was heard whistling the national anthem before a meeting with former chief executive Tung Chee-hwa a few days ago, Mr Tsang said it wouldn't be normal to have the same emotions all the time. 'Sometimes I will laugh, sometimes I may be a bit sad and worried ... this is normal for human beings.'