JavaFan's answer is definitely my suggestion,too. Only problems is that I'm curious: What about the case of a Lat or Long specified as +1.234 or +0.346? Don't you also want to allow the possibility of a single leading '+' charater?

Of course you probaby dont want a sigle '+' and a single '-', so that might be case where you'd need a construct something like the following in place of JavaFan's piece -? in his regex:

   (?:+?|-?)
[download]

Where the (?:  ) contruct is used to make it a non-capturing groupimg.