Try this:
window.location.href = "http://www.gorissen.info/Pierre/maps/googleMapLocation.php?lat="+elemA+"&lon="+elemB+"&setLatLon=Set";
To put a variable in a string enclose the variable in quotes and addition signs like this:
var myname = "BOB";
var mystring = "Hi there "+myname+"!";
Just remember that one rule!