Hide Url bar not working?

Hide Url bar not working?

I was told that JQM hides the url by default, but doesn't seem to be working on my site. Is there some trick to this? I've been reviewing the sites at http://www.jqmgallery.com/ and noticed that http://m.untappd.com/ was one of the few that did this.

I've tried many of the scrollTo examples with no luck.

thanks!