Those words mean "Happy New Year" in Vietnamese. Today is the first day of the New Year for Vietnamese, Chinese, Hmien, Tai Dam and probably many more people. Last night, there were many parties around Vientiane - everyone celebrates anyone's new year. People made offerings to the ancestors and piles of ghost money, paper clothing, shoes and "visas" for travel in the other world were all arranged on tables. Food offerings - fruit, specially cooked pork and whiskey - were also on the tables. The paper items for the dead are burned so they can receive the corresponding item in the spirit world. After the spirits have eaten enough of the spiritual essence of the food, the family on earth can eat the left over, physical part. People eat and drink until midnight, then light off firecrackers to drive off the bad spirits of the old year and welcome the new year.
Today, in the office, everyone was "chai loy," meaning floating spirit, spacey. We'll all be back to normal by tomorrow.