You can edit the post on the blackboard if and only if it is allowed by the Instructor. If there is no permission to either edit or delete then you cannot do so.
You can edit the post by clicking on your respective thread in the forum you will have list of possible functions click on edit and you can now edit your existing post and finally submit so that the changes can be viewed by everyone.
If you want to delete you can do with the same procedure but delete operation is irreversible.
i. The POST MESSAGE button can be used to publish.
ii. Click on EDIT button to change a message.
The message board is an online discussion inter-phase where people can hold conversations in the form of posted messages. In the internet forum, users with similar interests discuss topics, leave a reply or read a message.
After typing your message, you could publish or post it by pressing the POST MESSAGE button on the inter-phase. This operation makes it available to other users to read or react to it.
To edit or change a message, select the message and click on EDIT button and post it so that the changes can be viewed by other user's.