Hide Downloadlink ASP

[Blake2oo8]

i'am trying to hide the Downloadlink from some files. They're on a FTP. When i download a file then i can backtrack to the server and crawl some more files but i want to prevent that. I've already searched some solutions but i never got them working.I have a seperate download.ashx File with th following code. I't a example for only the file download.zip\[code\]Response.Clear()Response.ContentType = "application/x-zip-compressed" Response.AppendHeader("Content-Disposition", "attachment; filename=download.zip")Response.WriteFile(ftp://server.de/files/scripts/files/)Response.End()\[/code\]This is the Hyperlink for the download\[code\]<a href="http://stackoverflow.com/questions/12492389/download.ashx?download.zip" target=""_blank"">Click here to Download File</a>\[/code\]Everytime when I click the downloadlink i get a Runtime Error: \[code\]Server Error in '/files/scripts/files' Application.\[/code\]I hope you've some ideas to solve this problem.Thanks