file upload rename problems

Hi just having odd behaviour with some coding:

I have 2 pages one is ADD new image and the second is UPDATE image.

but im have a blonde moment it seems as for some reason I cannot get my head around the logic and I have tried different variations... for example of one of the variations that goes wrong....when an image uploads when it renames it creates a duplicate file extension on the new file on the server ( image.jpg.jpg) or it appends the file like so (image.jpg_1)

could you give me a rund down of which options to select for renaming:
from the Dynamic Data panel in File Manipulation Upload wizard I have many options to chose from ie:
1. Upload Files (imagefile)
status code
error messafe
client file name
file extension
server file name
service simple file name
.....
2 updateleaderboard (this is my html form)
imagefile
>imagefile Field Name
>imagefile temp path
>imagefile simple file name
.....

I have attached the 2 files to show my current image upload code....

All I want is to make sure the new file that's being uploaded will append _1 _2 etc on the end of the file (not on the end of .jpg extension as its currently doing)

Chris