Debugging & reference to .dll files

[Zeba]

Hi,

My client has given me some files in .dll form rather than the source
code itself ( say X.dll instead of X.cs ). So while debugging, at
points where there are references to functions in X.cs, I have to
"Step over" rather than "Step into" - Is that correct ? If I try step-
into I get an error/dialog box to locate the file. Is it that these
files ARE required or just that I can't step-into them ?

Thanks !