You pass the data in the URL like this:
http://domain.com?latdeg,latmin,N|S,londeg,lonmin,E|W,Label,Description
Where latdeg = is the degrees of latitude
latmin = the decimal minutes, convert the seconds and add to minutes
N|S = the hemisphere, N = North, S = South.
londeg = is the degrees of longitude
E|W = the other hemisphere, E = East, W =West.
Example: Position 48 38.772N and 122 19.91W, Current Position, All is going well!
http://www.svsarana.com/maps/map_app_3.htm?47,38.772,N,122,19.91,W,Current Position,All is going well!
This will generate a map with your label on it!