you can check
c:\WINDOWS\Microsoft.NET\Framework\{Version of asp}\Temporary ASP.NET Files\
You can find there a compiled version of your file (if you have not compiled it yet). From this version, you can easily restore your file by deleting some lines.
There is also a compilation DLL in this temporary directory, you can find the one that you missed, and this is the page you lost, and open it with NetReflector - there you can get the code that you miss with some kind of problem.
If you have Vista or Windows 7, there is also ShadowCopy, if it allows you to have some of the latest versions of your file, and you can get them just by looking at the properties of your file.
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