/*
 * menuDropdown.js - implements a dropdown menu based on a HTML list
 * Author: Dave Lindquist (http://www.gazingus.org)
 */

var currentMenu = null;

if (!document.getElementById)
    document.getElementById = function() { return null; }

var d, dom, ie, ie4, ie5x, moz, mac, win, lin, old, ie5mac, ie5xwin, op;

d = document;
n = navigator;
na = n.appVersion;
nua = n.userAgent;
win = ( na.indexOf( 'Win' ) != -1 );
mac = ( na.indexOf( 'Mac' ) != -1 );
lin = ( nua.indexOf( 'Linux' ) != -1 );

if ( !d.layers ){
	dom = ( d.getElementById );
	op = ( nua.indexOf( 'Opera' ) != -1 );
	konq = ( nua.indexOf( 'Konqueror' ) != -1 );
	saf = ( nua.indexOf( 'Safari' ) != -1 );
	moz = ( nua.indexOf( 'Gecko' ) != -1 && !saf && !konq);
	ie = ( d.all && !op );
	ie4 = ( ie && !dom );

	/*
	ie5x tests only for functionality. ( dom||ie5x ) would be default settings. 
	Opera will register true in this test if set to identify as IE 5
	*/

	ie5x = ( d.all && dom );
	ie5mac = ( mac && ie5x );
	ie5xwin = ( win && ie5x );
}

function initializeMenu(menuId, actuatorId) {
    var menu = document.getElementById(menuId);
    var actuator = document.getElementById(actuatorId);

    if (menu == null || actuator == null) return;

    //if (window.opera) return; // I'm too tired

    actuator.onmouseover = function() {
        if (currentMenu) {
            currentMenu.style.visibility = "hidden";
            this.showMenu();
        }
    }
  
    actuator.onmouseover_notsogood = function() {
        if (currentMenu == null) {
            this.showMenu();
        }
        else if (currentMenu) {
            currentMenu.style.visibility = "hidden";
            this.showMenu();
        }

        return false;
    }

    actuator.onclick = function() {
        if (currentMenu == null) {
            this.showMenu();
        }
        else {
            currentMenu.style.visibility = "hidden";
            currentMenu = null;
        }

        return false;
    }

    actuator.showMenu = function() {
        //menu.style.left = getPageOffsetLeft(this) + this.offsetWidth - 90 + "px";
        //if (mac && moz) {
	//        menu.style.left = getPageOffsetLeft(this) + 80 + "px";
        //	menu.style.top = getPageOffsetTop(this) + this.offsetHeight - 15 + "px";
        //} else { 
	//        menu.style.left = getPageOffsetLeft(this) + 40 + "px";
        //	menu.style.top = getPageOffsetTop(this) + this.offsetHeight - 15 + "px";
        //}
        menu.style.top = getPageOffsetTop(this) + 10 + "px";

        menu.style.visibility = "visible";
        currentMenu = menu;
    }
}

function getPageOffsetTop(el) {

  var y;

  // Return the x coordinate of an element relative to the page.

  y = el.offsetTop;
  if (el.offsetParent != null)
    y += getPageOffsetTop(el.offsetParent);

  return y;
}

function getPageOffsetLeft(el) {

  var x;

  // Return the x coordinate of an element relative to the page.

  x = el.offsetLeft;
  if (el.offsetParent != null)
    x += getPageOffsetLeft(el.offsetParent);

  return x;
}