The Canadian dollar has slipped to a two-week low against the greenback after crude prices dropped this week.At the beginning of the week, oil prices nosedived on the New York Mercantile Exchange amid concerns that demand recovery in China would be slower than anticipated.But while crude suffered further losses towards mid-week on the back of poor US employment data, a rally in equities helped the commodity to swing back towards the $69-a-barrel mark.Camilla Sutton, director of currency strategy at Scotia Capital in Toronto, a unit of the nation's third-biggest bank, told Bloomberg: "We saw the Canadian dollar weaken. Most of the commodity currencies are outperforming, but the Canadian dollar is lagging that move. It's more flow-driven as we move into the holidays."As Canada's biggest export, oil tends to have an acute effect on movements in the loonie, with the heightened winter demand likely to offer support to both crude prices and the Canadian dollar in the weeks ahead.