First Create Three Pages Names:
1. filelist
2. addthumb And
3. success

Now Open filelist Page And Paste this Code There.
[fm]d=all,l=50,o=u,s=||<div class="A2"><span style="color:#017122;"><b> <img src="https://i.extraimage.info/pix/FWImW.gif" alt=""> </b>%name%<br><a href="/page-addthumb?to-fid=%id%"><span style="float:left; background:darkcyan; padding-left:4px; padding-right:4px; padding-top:1px; padding-bottom:2px"><font color="white">Download it!</font></span></a></span></div><br><br>[/fm] :page: c=10,l=1::%prev=<img src="https://i.extraimage.info/pix/FW70k.png"> Previous% %next=Next <img src="https://i.extraimage.info/pix/FWtFq.png">%:/page:

And Open addthumb Page and Paste This Code There:
<h2> Set [fm]d=all,to=:to-fid(3):,no=not found..||%name%[/fm]</h2>[fm]d=all,to=:to-fid(3):,no=nay||<img src="%urlthumb%" alt="%name%"/>[/fm]<br>[setfm] to=:to-fid(3):,ud=site-success.html||Image Address: <br/> :var-thumbnail: :submit=Upload/Add:[/setfm]

At Last Open success page and paste this code there:
<script> alert(" Operation Success !!!\n\n Your Thumbnail Has Been Added Successfully And It Will Be Show In A Few Munites."); </script> <a href=":site_url:" style="display:block;"><< Go To Home Page</a>