PropertyChangeListener on TextField.Input

4.4.3.2, Polish, Writer
Windows 8.1, Polish

Document is Writer, with single Input field (nothing else in it), and here is my code:

Global oListener as Object
Global oVetoListener as Object
Global oInput as Object

Sub Listen
	oInput = GetTextInputField(ThisComponent, "a")
	oListener = createUnoListener("MyEvent_", "com.sun.star.beans.XPropertyChangeListener")
	oInput.addPropertyChangeListener("", oListener)

End Sub

Sub StopListen
	oInput.removePropertyChangeListener("", oListener)
End Sub

Sub MyEvent_disposing(oEvent)
	MsgBox "disposing"
End Sub

Sub MyEvent_propertyChange(oEvent)
	MsgBox "modified"
End Sub

Function GetTextInputField(Doc as Object, FieldName as String) as Object
	Dim TextFields as Object
	Dim TextField as Object
	TextFields = Doc.getTextFields.createEnumeration
	While TextFields.hasMoreElements()
		TextField = TextFields.nextElement()
		If TextField.supportsService("com.sun.star.text.TextField.Input") Then
			If TextField.Hint = FieldName Then
				GetTextInputField = TextField
			End If
		End If
	Wend
End Function

Sub ShowContent
	F = GetTextInputField(ThisComponent, "a")
	MsgBox F.getPropertyValue("Content")
End Sub

ShowContent shows Input field content corectly, so I assume GetTExtInputField works fine.
Unfortunately nothing happends on Content change. I have tried both

oInput.addPropertyChangeListener("", oListener)

and

oInput.addPropertyChangeListener("Content", oListener)

None of them works.
What is the problem?

“Content” is an attribute of “Input”, not a member of it’s property set. I suggest the modify listener.

I’m fairly new to Basic, with more expirience in python, but:
oInput.DBG_properties in Listen returns:
Properties of object “SwXTextField”:
SbxSINGLE IsFieldUsed;
SbxSTRING Content;
[…]
“Content” is listed as a property. I must be clearly missing something here on fundamental level if you are right.