MAP Global Variable and USE with Cumulative Functoid

This funtoid should be connected to single occuring unique element like GUID from Input MAP so that for each new records its value will get reassigned( to empty "").

First Scirpting Functoid with two Input:

public void GetTelephone(string UPPhonenum, string Phonenum)
        {
            if (UPhomePhone.Equals(String.Empty))
            {
                UPhomePhone = UPPhonenum;
            }
            if (homePhone.Equals(String.Empty))
            {
                homePhone = Phonenum;
            }
        }
================
Cumulative Funtoid: Scripting, Constant 1
====================
Scirpting Functoid Connected to Top element of output schema in Pic. above:

public string retHomeNum(string IgnoreValue)
        {
            if (!String.IsNullOrEmpty(UPhomePhone))
                return UPhomePhone;
            else
                return homePhone;
        }

====================
Middle element in Output Schema:

public string retOfficePhone()
        {
            if (!String.IsNullOrEmpty(UPofficePhone))
                return UPofficePhone;
            else
                return officePhone;
        }
======================