Thank you for the help. I am sure I am still doing something wrong.

If I copy the statement in as written I get an error on XDocument.dom that
says "Reference to non-shared member requires an object reference.

And I am nit sure what my xpath should say. The form name is
Project_Approvals and the Field name is Approver_name so should it be. /my:
Project_Approvals/my:Approver_Name

Thank you for the help. I really appreciate it.
Here is all the code.

 Public Sub _Startup(ByVal app As Application, ByVal doc As XDocument)
           thisXDocument = doc
           thisApplication = app
           ' You can add additional initialization code here.
       End Sub

<InfoPathEventHandler(MatchPath:="CTRL4_7", EventType:=InfoPathEventType.
OnClick)> _
       Public Sub CTRL4_7_OnClick(ByVal e As DocActionEvent)
           ' Write your code here.
           Dim myField
           myField = "I am new with infopath"
           XDocument.DOM.selectSingleNode("/my:myFields/my:Approver_Name").
text() = myField
       End Sub