1) add your domain to property and verify it. sign in required
Add Property
2) Insert this script into "< head>< /head>" tags
3) add this 'id' and 'list' attributes to your city < input> tag
4) add this DIV after the city textbox (< input> tag)
5) add this 'id' to your postal code < input> tag
6) add this code before < /body> tag