# EVTWIN

> [HTML Version](evtwinsbr.htm)

_Reviewed and revised April 2024_

**xcall EVTWIN, opcode, \{,arg1, ...\}**

The subroutine EVTWIN displays messages to the system message window. It is primarily used internally to implement the TRACE and DEBUG statements, which are translated into EVTWIN statements by the compiler, but can be called directly like any other subroutine.

**Parameters**

_opcode_  ([Bitmap](bitmap.md) 16)  \[in\]

Action to perform, coded per the following table.  Specify one of the first three options (Open, Print, Close) and zero or more of the last two.

| **Value** | **Meaning** |
|------|------|
| \&h0001 | Open |
| \&h0002 | Print |
| \&h0003 | Close |
| \&h0100 | Debug (versus trace) |
| \&h0200 | Pause (wait for double-click) |




_arg1, ..._  ([String](string.md) or [Num](num.md))  \[in\]

zero or more arguments whose values will be displayed in a single output line

**Comments**

If you don't like the way the TRACE.PRINT statements look, you can replace the internal EVTWIN with your own EVTWIN.SBX.

**See Also**

•	[TRACE statements](trace_statements.md)

•	[Event Tracing](eventtracing.md)