How can you look at the source code of a transaction in SAP?
Three options come to mind (I am sure there are many more):
1) In the transaction: menu System --> Status, the pop-up will show the program, double-click on it and it should take you there
2) Transaction SE93 is the transaction maintenance
3) Table TSTC keeps transaction codes and programs.
You can see the source code of a program in transaction SE80
You can go to System -> Status
and see the program name there.
After that you can go to Tcode SE38
or SE80
to view the coding.
Alternatively, you could key in /h to activate the debugging mode before you run the transaction.
The exact answer to your question would be
?SYNTAX ERROR
A transaction does not have source code to look at. Take a look at various transactions using the transaction SE93. A transaction may name a program (report) to be executed - then you'll have to take a look at the source code of that program. A transaction may name a screen of a program, function pool or module pool to show - then you'll have to examine this screen and the subsequent ones. A transaction may simply delegate to another transaction using a variant, then you'll have to follow this link. Read this for more info on the various types of transactions and what they are good for.