It is strongly advised by me, your local mother-figure, 76, to edit your posts rather than post several separate ones.

Having the edit-post function is a blessing that you may take for granted. Allow me to emphasize it's usefulness.

Say you're playing in an rp and you spend about an hour, maybe even two hours writing up a nice long, detailed post. You're reading over the finished product, you see no faults in grammar or writing what-so-ever and your finger slides over that 'post message' button. Suddenly! You see, out of the corner of your eye, a typo that you had ironically missed during the once-over. It's too late. The post has been made. You read the post in it's 'set-in-stone' place in the thread, and you realize that in your rush, you missed several typos. If only you had an edit button! You could edit the post and fix all the typos as many times as it took to fix them all.

Simply go beneath any post you've ever made(if it is in a locked thread, you cannot edit your post.) and click the 'edit' button', this will turn the post into a message box, inside the message box will be all the code you used in the post.
Now, at this point, you have two options: You can edit the post, add or take away, fix grammar, spelling, paragraph arrangement, etc, or you could simply delete the post entirely.

To delete the post, go down to the edit button and click it, now that the post is in it's 'post-box' form, you can go right in-between 'Go advanced' and 'Cancel' you will see 'Delete', click this and it will drop down another section. Within this you will find two options. To delete the post, or not to delete the post.
Select 'delete message' and click the 'delete message' button right below the two options. The post will be removed and the ones above and below will be directly connected in it's place.