/**
 * landgate_popup.js
 * 
 * JavaScript functions to handle browser window management.
 */
/**
 * Open the specified URL in a new popup window, which is resizable and scrollable but
 * does not have a location bar, status bar or menu bar.
 *
 * NOTE: To use this function, you must not break accessibility for users that do not
 * have JavaScript enabled.  The HTML code to open a page at the address "/page.html"
 * is as follows (note the "return false" part, it is important):
 * 
 * <a href="/page.html" target="_blank" onclick="javascript:popupURL('/page.html'); return false;">...</a>
 *
 * @param url The URL to open.
 * @param popupWidth (OPTIONAL) Width of the window to open; defaults to 800.
 * @param popupHeight (OPTIONAL) Height of the window to open; defaults to 600.
 */
function popupURL(url, popupWidth, popupHeight) {
  // Assign default values to arguments.
  popupWidth = popupWidth ? popupWidth : 900;
  popupHeight = popupHeight ? popupHeight : 700;
  // Get the size of the screen.
  var screenWidth = window.screen.width;
  var screenHeight = window.screen.height;
  // Determine the on-screen position (x, y).
  var x = (screenWidth - popupWidth) / 2;
  var y = (screenHeight - popupHeight) /2;
  // Open the window for the specified URL.
  var options = 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width='+popupWidth+',height='+popupHeight+',left='+x+',top='+y+',screenX='+x+',screenY='+y;
 window.open(url, "_blank", options);
}
/**
 * Centre the current window on the screen, after setting it to the specified size.
 * 
 * @param width Width for the window, defaults to 800.
 * @param height Height for the window, defaults to 600.
 */
function centreWindow(width, height) {
  // Assign default values to arguments.
  width = width ? width : 800;
  height = height ? height : 600;
  // Get the size of the screen.
  var screenWidth = window.screen.width;
  var screenHeight = window.screen.height;
  // Determine the on-screen position (x, y).
  var x = (screenWidth - width) / 2;
  var y = (screenHeight - height) /2;
  // Set the size and position.
  window.resizeTo(width, height);
  window.moveTo(x, y);
}