netscape	= (document.layers) ? 1:0;
goodIE		= (document.all)? 1:0;
netscape6   = ((document.getElementById) && (!goodIE)) ? 1:0;
var menupos = 180;
var MENU_LENGTH = 0;
var OPEN_MENU = null;
var ROLLED_OVER = 0;

var cambridge = new addmenuitem("text1", "cambridge",-53,0);
var cursos = new addmenuitem("text2", "cursos",0,98);
var servicios = new addmenuitem("text3", "servicios",23,230);
var informacion = new addmenuitem("text4", "informacion",60,146);
var aula = new addmenuitem("text5", "aula",85,0);
var banner = new addmenuitem("text6", "banner",175,0);

// el primer numero indica cuantos pixeles tiene que moverse el menú que nosotros clickleamos para cerrarlo
// el segundo numero indica cuantos pixeles tiene que moverse el menu siguiente al hacer click en el menu anterior

var menu = new Array(cambridge,cursos,servicios,informacion,aula,banner);

function addmenuitem(textdiv,divname,startpos,wordheight)	{
	this.text = textdiv;  // identifies div holding this menuitems text
	this.name = divname;  // identifies div holding this menuitems image
	this.startpos = startpos + menupos;  // used with style.top to set location
	this.wordheight = wordheight; // used to determine how far to open emnu
	
	this.positioninmenu = MENU_LENGTH++; // identifies position in menu, used to record and check if
};										 // this is the image that is open, and to start opening menuitmes
										 // from this point in the menu on.
										 								
function hideWords()	{
	if(goodIE)	{
		for(a=0;a<menu.length;a++)	{
			divtag = eval('document.all.' + menu[a].text);
			divtag.style.visibility = "hidden";
		}
	}
	if(netscape)	{
		for(a=0;a<menu.length;a++)	{
			divtag = eval('document.' + menu[a].text);
			divtag.visibility = "hidden";
		}
	}
	if(netscape6)	{
		for(a=0;a<menu.length;a++)	{
		document.getElementById(menu[a].text).style.visibility="hidden";
		}	
	}
};


function toggleWords(menuitem)	{
	hideWords();
	if(goodIE)	{
		divtag = eval('document.all.' + menuitem.text);
		divtag.style.visibility = "visible";
	}
	if(netscape)	{
		divtag = eval('document.' + menuitem.text);
		divtag.visibility = "visible";
	}
	if (netscape6)	{
		document.getElementById(menuitem.text).style.visibility="visible";
	}
};

function closemenu()	{
	if((goodIE) && (OPEN_MENU!=null))	{
		for(a=OPEN_MENU;a<menu.length;a++)	{
			divname = eval('document.all.' + menu[a].name);
			divname.style.top = menu[a].startpos;
		}
	}
	if((netscape) && (OPEN_MENU!=null))	{
		for(a=OPEN_MENU;a<menu.length;a++)	{
			divname = eval('document.' + menu[a].name);
			divname.top = menu[a].startpos;
		}
	}
	if((netscape6) && (OPEN_MENU!=null))	{
		for(a=OPEN_MENU;a<menu.length;a++)	{
			document.getElementById(menu[a].name).style.top = menu[a].startpos;
		}		
	}
	closeOpenImage();
	hideWords();
	OPEN_MENU = null;
};

function updateMenu(menuitem)	{
	if (menuitem.positioninmenu != OPEN_MENU)	{ //if this menu item is not open
		closemenu();  // closes open menu item
		openImage(menuitem); // swap image with open state image
		if(goodIE)	{  // open menuitem for IE
			for (a=menuitem.positioninmenu+1;a<menu.length;a++)	{
				divname = eval('document.all.' + menu[a].name);
				divname.style.top = menu[a].startpos + menu[menuitem.positioninmenu].wordheight;
			}
		}
		if(netscape)	{ // open menuitem for netscape 4
			for (a=menuitem.positioninmenu+1;a<menu.length;a++)	{
				divname = eval('document.' + menu[a].name);
				divname.top = menu[a].startpos + menu[menuitem.positioninmenu].wordheight;
			}
		}
		if(netscape6)	{ // open menuitem for netscape 6
			for (a=menuitem.positioninmenu+1;a<menu.length;a++)	{
				document.getElementById(menu[a].name).style.top = menu[a].startpos + menu[menuitem.positioninmenu].wordheight;
			}		
		}
		toggleWords(menuitem);  // make words for that menuitem visible, hide the rest
		OPEN_MENU = menuitem.positioninmenu; // record which menuitem is now open
	}
	else	{  // if this menu item is open
		closemenu();
	}
};


function openImage(openItem)	{
	if(goodIE || netscape6)	{
		changethisimage = eval("document." + openItem.name + "_image");
		ROLLED_OVER = openItem.positioninmenu;
	}	
};

function closeImage()	{
	if(goodIE || netscape6)	{
		if(OPEN_MENU != menu[ROLLED_OVER].positioninmenu)	{
			closethisimage = eval("document." + menu[ROLLED_OVER].name + "_image");
		}
	}
};

function closeOpenImage() 	{
	if(goodIE || netscape6)	{
		if(OPEN_MENU!=null)	{
			closethisimage = eval("document." + menu[OPEN_MENU].name + "_image");
		}
	}
};