Create central user account in Q1IM

I have the following script to create the central user account= First Initial and lastName.If the same first name and last name exist add numerical valvue to the UserID created. But my script is creating only LastName as Central User Account. Please help?

Here is my script:

#If Not SCRIPTDEBUGGER Then
Imports System.Collections.Generic
Imports System.Data
#End If

Public Function AFO_BuildCentralAccountGlobalUnique(ByVal uid_person As String, ByVal Lastname As String, ByVal Firstname As String, ByVal FirstInitial As String) As String
          
Dim i As Int32
            Dim account As String
            Dim accountPrefix As String
            Dim f As ISqlFormatter = Connection.SqlFormatter

            AFO_BuildCentralAccountGlobalUnique = String.Empty
  
   Firstname = VI_AE_FormatConvertUmlaut_Sonderzeichen(Firstname)
   Lastname = VI_AE_FormatConvertUmlaut_Sonderzeichen(Lastname)
  

  
            If Firstname.Length > 0 And Lastname.Length > 0 Then
                If FirstInitial.Length + Lastname.Length <= 19 Then
     account = FirstInitial &  Lastname
    Else
     account = FirstInitial & Lastname.Substring(0, 1)
    End If
  
            ElseIf Firstname.Length > 0 Then
                account = FirstInitial &  Lastname
            Else
                account = FirstInitial & Lastname.Substring(0, 1)
            End If

            'account = VI_AE_FormatConvertUmlaut_Sonderzeichen(account)
            accountPrefix = account

            'fill existing addresses in a dictionary
            Dim existing As New Dictionary(Of String, Object)(StringComparer.OrdinalIgnoreCase)
            Dim dummy As New Object()
            Dim dummyPerson As ISingleDbObject
            dummyPerson = Connection.CreateSingle("Person")
            Dim pattern As String = accountPrefix & "%"
            Dim myObjectKey As New DbObjectKey("Person", uid_person)

            Using rd As IDataReader = CType(dummyPerson.Custom.CallMethod("SearchCentralAccount", pattern), IDataReader)

                While rd.Read()
                    Dim accountName As String
                    Dim objectKeyString As String
                    Dim objectKey As DbObjectKey

                    accountName = rd.GetString(rd.GetOrdinal("AccountName"))
                    objectKeyString = rd.GetString(rd.GetOrdinal("ObjectKeyPerson"))

                    If Not String.IsNullOrEmpty(objectKeyString) Then
                        objectKey = New DbObjectKey(objectKeyString)

                        'only addresses which not belong to the actual employee will be considered
                        If myObjectKey.Equals(objectKey) Then
                            Continue While
                        End If
                    End If

                    existing(accountName) = dummy
                End While
            End Using

            While True
                Dim centralAccount As String = account

                ' Does not exists?
                If Not existing.ContainsKey(centralAccount) Then
                    Return centralAccount.ToLowerInvariant()
                End If

                ' next trial
                i = i + 1
    If i = 1  And account.Length <= 18 Then
     account = accountPrefix & FirstInitial.Substring(0, 1) & Lastname

    ElseIf account.Length <= 19 And i <= 9 Then
                 account = accountPrefix & CStr(i)
    ElseIf i <= 9 Then
     account = accountPrefix.Remove(accountPrefix.Length - 1, 1) & CStr(i)
    Else
     account = accountPrefix.Remove(accountPrefix.Length - 1, 2) & CStr(i)
    End If
            End While
End Function