Pass url parameters using WebBrowser control

Hi,
I m trying to pass parameters to htm file using webbrowser control.
if i m trying to use : WebBrowser.Navigate(map.htm?lat=12)
there is some problem with the ' ? ' character.



but when the map.htm file tries to get the parameter (long1) its always get "Undefined" value.
in contrast if im just opening my chrome browser and in the url wrtie c:\path\map.htm?long1=12
the return value is ok - 12
any suggestions ??