How do i get the object from one sub to the other sub - vb.net

Question

What i am trying to do is to get the intGuestID1 from page_load to be used in bth_add area
Because i am trying to get the ID when it has been clicked from another form to frmAddFollowUp so i tried to request it from the page_load as when i request from the add button, it only gives me the number 0 instead of the id from the previous form.
Partial Class frmAddFollowUp
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim objCDBFeedback As New CDBFeedback
Dim objCDBDepartment As New CDBDepartment
Dim intGuestID1 As Integer
Dim arrList As New ArrayList
If Page.IsPostBack = False Then
intGuestID1 = Request.QueryString("id")
arrList = objCDBDepartment.getAllDepartmentDropDownList
lstDepartment.DataSource = arrList
lstDepartment.DataTextField = "DepartmentName"
lstDepartment.DataValueField = "Department"
lstDepartment.DataBind()
End If
End Sub
Protected Sub btnAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAdd.Click
Dim CheckBoolean As Boolean = True
Dim objCDBFeedback As New CDBFeedback
Dim objCFeedback As New CFeedback
If txtStaffName.Text = "" Then
lblValidateStaffName.Text = "*Please enter Staff Name."
CheckBoolean = False
Else
lblValidateStaffName.Text = ""
End If
If txtFollowUpSummary.Text = "" Then
lblValidateFollowUpSummary.Text = "*Please enter Follow up summary."
CheckBoolean = False
ElseIf txtFollowUpSummary.Text.Contains("'") Then
txtFollowUpSummary.Text = txtFollowUpSummary.Text.Replace("'", "''")
Else
lblValidateFollowUpSummary.Text = ""
End If
If txtAmount2.Text = "" Then
lblValidateAmount2.Text = "*Please enter the Amount or put in NIL if there is no amount."
CheckBoolean = False
Else
lblValidateAmount2.Text = ""
End If
If CheckBoolean = False Then
If txtStaffName.Text.Contains("''") Then
txtStaffName.Text = txtStaffName.Text.Replace("''", "'")
End If
If txtFollowUpSummary.Text.Contains("''") Then
txtFollowUpSummary.Text = txtFollowUpSummary.Text.Replace("''", "'")
End If
Else
Dim intNumOfRecordsAffected As Integer
objCFeedback.GuestId = intGuestID1
objCFeedback.Feedback = txtFollowUpSummary.Text
objCFeedback.Department = lstDepartment.SelectedItem.Value
objCFeedback.StaffName = txtStaffName.Text
objCFeedback.Amount = txtAmount2.Text
intNumOfRecordsAffected = objCDBFeedback.addNewFollowUp(objCFeedback)
Response.Redirect("frmIncident.aspx")
End If
End Sub

Answer 1

You may either specify ByRef parameter type or use Function that returns reference of an object. In your code-snippet, you may declare variable at class-level (fields) so you may use them in different event handlers/sub.

Answer 2

Make intGuestID1 a private member variable. That will allow you to access this variable in both functions.
Is this code compiling? I do not see intGuestID1 being declared in btnAdd_Click, this should be throwing an error.
To declare a private member variable add the following above the Page_Load function, for example:
Partial Class frmAddFollowUp
Inherits System.Web.UI.Page
Private _intGuestID1 as Integer ' The _ prefix is just a naming convention that is used for class member variables, if you don't like it, you can remove it.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Now, in your Page_Load method, remove the line Dim intGuestID1 As Integer, as you no longer need to declare this. Finally, anywhere you see intGuestID1, rename it to _intGuestID1
Also, some ways to possibly refactor this is to create a Read Only Property that encapsulates the fact that you're getting _intGuestID1 from the QueryString. See the following example:
Private ReadOnly Property GuestID1() as Int32
Get
Return Request.QueryString("id")
End Get
End Property
One of the benefits of doing this is to perform any checks on the value before using it, such as, is it an actual number that is stored in Request.QueryString("id"), or is the user allowed to have access to the entity represented by this id, or whatever else you can think of. When you do this, you'll need to change all references to _intGuestID1 to GuestID1.