street elements null in IE8

when editing address elements in the contact edit form using IE8, toggling to the elements view will put "null" in any fields that have no content. this is reproducible on the sandbox.

I think that the eval() statement resolves to null, which in most browsers just displays as an empty field. but in IE8 it actually inserts the text "null"

I can fix it with:
var streetName = eval( "allAddressValues.street_name_" + blockId );
if (streetName == null)

{ streetName = ''; }

var streetUnit = eval( "allAddressValues.street_unit_" + blockId );
if (streetUnit == null)

{ streetUnit = ''; }

var streetNumber = eval( "allAddressValues.street_number_" + blockId );
if (streetNumber == null)

{ streetNumber = ''; }

var streetAddress = eval( "allAddressValues.street_address_" + blockId );
if (streetAddress == null)

{ streetAddress = ''; }

but that's probably not the best way to address the issue.