Almost every kid will wet the bed at some stage. As a parent, the key to supporting your child through this sensitive time is to not make a big deal out of it.
Always try to keep positive and never punish your child for wetting the bed. It is a total myth that children wet the bed because they are naughty or lazy. Bedwetting is completely outside of their conscious control, so no amount of punishment is going to help them stop bedwetting and will only damage their confidence and self-esteem.
Equally, rewards need to be used wisely, if you decide to use them at all. Rewarding your child for staying dry at night will only set them up for disappointment if they fail to achieve something that they have no control over in the first place.
In most cases bedwetting is caused by a developmental delay that will naturally fix itself with the grace of time, so your consistent loving support will make for smooth sailing while this phase passes by.