Simple Menus

The simplest menu example , just uses the "helloworld" example, but add a menu with three buttons to change the color of the map . The code is very simple. A menu is created with pairs of text/functions:
var m = new menu("red",setRed,"green",setGreen,"blue",setBlue)
Each pair consists of the text that is put on the button, and a user defined function that is called when the button is clicked. The three functions just set the color or the map and submit the window, e.g. for blue:
function setBlue()
    w.setVar("map_countries_class_color","0 0 255")
    w.submit()
}
Menus are not visible by default: most menus you create will be submenus that appear from other menus and disappear when clicked. A menu that should stay on screen has to call two additional methods:
m.realSticky(true)    // menu remains on screen with blue border
m.showAt(left,top)    // initial position
Once the menu appears on screen, it can be moved or toggled from horizontal to vertical (shift-click the blue border).