Omitting pictures in the view that have not been uploaded.

Omitting pictures in the view that have not been uploaded.

I have built an upload form that will upload pictures to a specific size using the formula field. This is the formula that I'm using:
"<img src='http://creator.zoho.com/DownloadFile.do?filepath=/" + Picture_1_Upload + "&sharedBy=" +zoho.adminuser+"' alt='Display Uploaded Images in Zoho Creator' width='320' height='240'/>"
 
With this everything works as it should except when a picture is not uploaded there is a 320x240 blank square in the view of the form. I have 4 fields for pictures but at times end user may not need to upload 4 pictures and I would like the view to not display the blank 320x240 square.
 
Can I use "if" or something like that?
 
Thanks for the help