Remainder Mail agent - lotus-notes

Question

I have form with 3 fields adress,status,ReportingDate.
Adress field contains the ID where the mil has to be sent.
Now I have created an agent where it should mail to the data present in adress field when status is incomplete and reporting date is exactly 7 days before todays date.
My Code:
Option Public
Option Declare
Sub Initialize
Dim sess As New NotesSession
Dim db As NotesDatabase
Dim doc As NotesDocument
Dim timestamp As New NotesDateTime("Today")
Dim Noresponsedate As NotesDateTime
Dim vw As NotesView
Dim diff As Integer
Dim SendTo As Variant
Call timestamp.SetNow()
Set db = sess.CurrentDatabase
Set vw = db.GetView( "data" )
Set doc = vw.GetFirstDocument()
While Not doc Is Nothing
If doc.Status(0) = "Incomplete" Then
Call checktimedifference(doc)
End if
Set doc = vw.GetNextDocument(doc)
wend
End Sub
Sub checktimedifference(doc As NotesDocument)
Dim due As NotesDateTime
Dim present As NotesDateTime
Dim timecheck As variant
Set due = New NotesDateTime ( "" )
Set present = New NotesDateTime ( "Today" )
timecheck = doc.ReportingDate(0)
due.LSLocalTime = timecheck
If due.TimeDifference (present) = -604800 Then
Call sendmailtouser(doc)
End If
End Sub
Sub sendmailtouser(doc As NotesDocument)
Dim db As NotesDatabase
Dim rtiitem As NotesRichTextItem
Dim maildoc As NotesDocument
dim recepient As variant
Set maildoc = New NotesDocument( db )
Set rtiitem = New NotesRichTextItem( maildoc, "Body" )
recepient = doc.adress(0)
maildoc.from = db.Title
maildoc.form = "memo"
maildoc.subject = "A Minor Injury Report:" & doc.Seq_No(0) & " needs your response"
maildoc.SendTo = recepient
Call rtiitem.AppendText( "Please respond to this Minor Injury Report" )
Call rtiitem.AddNewline( 2 )
Call rtiitem.AppendText( "Your response for the Minor Injury Report: " & doc.Seq_No(0) & " is required" )
Call rtiitem.AddNewline( 2 )
Call rtiitem.AppendText( "Please click on the following link to access the document.")
Call rtiitem.AppendDocLink( doc, db.Title )
Call maildoc.Send(False)
End Sub
When I am running the agent on client I am getting the following error:
Please help me to solve the error and send mail to the recepients.

Answer 1

Not using any error handling is very bad practice. But your error will most probably happen in the sendmailtouser- sub, where you dim a local notesdatabase- object named db without actually initializing it.
The line
set maildoc = New NotesDocument( db )
will fail.
Either declare db globally and set it in your initialize or dim ses in that sub again and set db again (worst case as you have to do it for every document)