javascript to insert address with checkbox option causing clearing of user entered address on save

I have a checkbox that will enter our company address into the address fields when checked, but when unchecked the user has the option to enter their own address.

This works fine until it comes to saving the document. When the checkbox is unchecked and the user enters their own address and then saves the document, the javascript is removing the user entered address.

Here is the code:

<eventactivity="initialize"name="event__initialize">
<script>if($.rawValue eq 1) then 
form1.Main.Address1="blah blah Street"
City="London"
ZipCode="WC1N XXX"
Country="UK"
elseif (ros.rawValue eq 1) then 
form1.Main.Address1="blah blah Street"
City="London"
ZipCode="WC1N XXX"
Country="UK"
else 
Address1 = null
City = null
ZipCode = null
Country = null
 endif 
</script>
</event>
<eventactivity="change"name="event__change">
<script>if($.rawValue eq 1) then 
form1.Main.Address1="blah blah Street"
City="London"
ZipCode="WC1N XXX"
Country="UK" elseif (ros.rawValue eq 1) then 
form1.Main.Address1="blah blah Street"
City="London"
ZipCode="WC1N XXX"
Country="UK"
else 
Address1 = null
City = null
ZipCode = null
Country = null
 endif
</script>
</event>

Any ideas?

EDIT:

It's this part of the script that is causing it:

    else

    Address1 = null

    City = null

    ZipCode = null

    Country = null

I need a way to say user-entered-data:

    else

    Address1 = user-entered-data

    City = user-entered-data

    ZipCode = user-entered-data

    Country = user-entered-data

(Notes: I am saving it as a reader-extended pdf so the text entered in the fields by the user can be saved)

Thanks in advance