How to set curd at home

Heat milk in a saucepan till it is a little hot than lukewarm. Transfer it to a container,where you want to set it. Take 1 tea spoon of curd and mix it to the milk.Cover the lid of the container and set aside to set.If the outside temperature is hot, it will set in 2 hrs.But in  case it's cold outside, you may need to set it overnight.