Debug Lotus Notes applications

I would like to present which approaches I use during debugging LN applications. I would be happy if anybody add new interesting approaches.

[@Formula]
- @Prompt and @StatusBar – the easiest way to debug code written on @Formula
- Field Debug_Fld := value_debug
- @MailSend – for code that runs on server (sch. agents)
- notes.ini - I don't like this approach because of size of variables

Example
strA := "ABC"; strB := "DEF";
strC := strA + strB;
@Prompt([ok]; "strC";"strC = " + strC);
@StatusBar("strC = " + strC);
Field Debug_FieldName := strC;
@MailSend("username";"";""; "debug strC"; ""; "strC = " + strC);

[Lotus Script]
- Lotus Script Debugger as tool for debugging
- Print, MsgBox, NotesLog, Stop, on erorr goto errh

Example
Dim strA As String
Dim strB As String
Dim strC As String
strA = "ABC"
strB = "DEF"
strC = strA & strB
Print "strC = " & strC
Msgbox "strC = " & strC
Stop 'enable debugger require
Dim currentLog As New NotesLog( “debug log 1" )
Call currentLog.OpenFileLog( "c:\log.txt" )
Call currentLog.LogAction( "strC = " & strC)
Call currentLog.Close

[Schedule Agents]
- remote debugger (it is easy to enable it if you read help)
- send an email, msgbox (log.nsf), noteslog

[JavaScript]
- alert(value);
- try – catch();
- Microsoft script debugger \ Mozilla firebug \ Chrom debugger

Lets catch the next simple error

Example
code on the button use call function add, the body of function below
function add(frm){
var i1 = frm.Number1.value;
var i2 = frm.Number2.value;
var fld = frm.total;
fld.value = i1 + i2;
}
when we call function we will see next error:
what it could be? it does not provide us enough information (I think so). Now enable ie debugger
click Yes
Now we see where is error, but still could not understand "why?"
Now we are definitely close to solve the problem, we see that we did not take "number" field. Why we did not take number field? yes because of small first letter. We should wrote Number but not number.

[Java]
- Java debug console (System.out.println(“text”);
- Try / catch with NotesError and NotesException classes
- Remote java debugging with Eclipse

also I would like to recomend you external LN application openlog.nsf