A retired primary school principal was convicted yesterday of conspiring with suppliers to inflate invoices to cheat the school of more than $120,000. So Chi-cheong, 65, who was principal of the Sam Shui Natives' Association School in Tai Po, pleaded guilty to one count of accepting advantages, two of conspiracy to use documents with intent to deceive, and one of fraud. He had previously denied the charges. The defendant's lawyer, Lawrence Lok SC, told District Court Judge Peter Line that So - who had worked at the school for 40 years, first as a teacher and then as principal for 26 years - had acted foolishly and was a victim of his own misdeed. 'His fall from grace must be enormous,' Mr Lok said, adding that his client's downfall had also brought disgrace to his wife, 63, a retired headmistress. He said So was willing to compensate the management committee of the school. Mr Lok said So had been making donations to various school scholarships and had spent at least $45,000 from his own pocket to support and finance school activities, furniture and premises. He submitted three letters - from the school's management committee, its president and the Parent Teacher Association - commending So's enthusiasm and leadership at the school. The court heard So had asked Chan Kam-nam, an operator of uniforms supplier Tai Tung Hong, to supply stationery to the school between September 1998 and September 2002, when he retired. Mr Chan obtained the items from the school's stationery supplier and marked up the prices. So then arranged payment to Tai Tung Hong and received $10,000. On another occasion So told four school janitors to make dresses for dancing competitions and asked Mr Chan to issue 25 invoices from the firm totalling $55,552. So also conspired with Lau Sun-youi, owner of stationery supplier Tai Hing, to issue four bogus cash memos amounting to $55,188, between January 1999, and September 2002. Sentencing will be carried out today.