TOPIC: Deleting pictures

I must be doing something wrong when I delete a picture from the server.  The few times I have deleted one, I did it like this:  I was in the process of inserting a picture so I browse the server.  The picture I was about to insert was to replace another one so while I was in the Image/File Browser, I would delete the one that was to be replaced.  The picture always disappeared but always with a message that said: error deleting file. 
I have been noticing that occasionally a picture will be missing from my site.  All the image property details would still be there but no image.  I'm thinking there may be a connection.
What is the proper procedure for deleting an image?
Thanks.

If you delete the image from the file browser it will be gone, but that doesn't mean that it will automatically the attempt to add that image to any page you have. So if you add an image to 5 pages and delete the image from the file browser, you're going to have 5 pages with a box where the image should be. You'd need to edit those pages and remove the box where the image should be as well.

Yes, I understand that.  What I was doing is delete the image I don't want.  It would give me an -error deleting image- message but the image was gone so I carried on with uploading the new image.  Everything good so far...until I noticed that an image would be gone on a page that I was not editing.  I was wondering if that could be related.  Why would an image disappear without me touching it not intentionally anyways.
I was wondering if I have to delete an image some other way.

Did the other image have the same file name? Was it the same image?

It wasn't the same image and it couldn't have the same file name could it?  I have tried to load a picture that was already on the server.  The name automatically had a 0 added to give it a unique name. 
If there is nothing obvious in what I am doing wrong then don't worry about it.  I was thinking there must be a way to delete an image without having to go through the "insert image" icon.

Sure, you can click on any image then click on the delete button and it will go away. You can even use delete or the backspace button on the image.