How do I find out what caused a deadlock?

I got an error message from my customer saying that once, during the night,
when executing a report it got an error message that stopped the application
the extended error was
Transaction (Process ID 57) was deadlocked on lock resources with another
process and has been chosen as the deadlock victim. Rerun the transaction.
Thats fine but It was an untrapped error that required a stop and start of
the application and its the first time it occured in seven years of running
this app. The app is a report, so everyting is read-only, there are no
record editing or creations involved, so how can it create a deadlock?
To answer these questions I think I need to know what the conditions were
that created the deadlock, I think that may be possible looking through the
transaction log of sql server, but how do I do that? When I looked under
administration logs in the sql server explorer all I saw was basically the
logs of the backups , but no place where I could find what transact sql
statement executed at what time with what results. Is there a way to find
this out or is that info lost after commandes execute?
Thanks for your help,
BobHere is a start
http://support.microsoft.com/defaul...kb;en-us;832524
Denis the SQL Menace
http://sqlservercode.blogspot.com/|||Thanks Denis
"SQL" <denis.gobo@.gmail.com> wrote in message
news:1144345622.731620.232190@.v46g2000cwv.googlegroups.com...
> Here is a start
> http://support.microsoft.com/defaul...kb;en-us;832524
> Denis the SQL Menace
> http://sqlservercode.blogspot.com/
>