A retired primary school principal was sentenced to one year in jail yesterday for swindling his school by inflating invoices. He was also ordered by District Court Judge Peter Line to hand over the more than $120,000 he had cheated out of the school between 1998 and 2002. So Chi-cheong, 65, was a principal of the Sam Shui Natives' Association School in Tai Po. He originally denied the charges of accepting advantages, two of conspiracy to use documents with intent to deceive, and one of fraud, but later changed his plea to guilty to one count. So's lawyer, Lawrence Lok, SC, told the court that the former principal's fall from grace was enormous. He produced letters from the school's management committee and its Parent Teacher Association commending So's enthusiasm and leadership over 40 years - first as a teacher and then as principal for 26 years. Mr Lok also said So's fall from grace had brought shame on his wife, a retired headmistress. But Judge Line sentenced So to a year in jail for breaching his position of trust at the school. The court heard So had asked Chan Kam-nam, who worked for a school uniforms supplier, Tai Tung Hong, to supply stationery to the school between September 1998 and September 2002. Mr Chan obtained the items from the school's stationery supplier, but 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.