function openWindowFixedSize(url,var_width,var_height) {

	agent = navigator.userAgent;
	windowName = "Console";
	
	params = "";
	params += "toolbar=0,";
	params += "location=0,";
	params += "directories=0,";
	params += "status=0,";
	params += "menubar=0,";
	params += "scrollbars=0,";
	params += "resizable=0,";
	params += "width=";
	params += var_width;
	params += ",height=";
	params += var_height;
           
	win = window.open(url, windowName , params);
	
	if (agent.indexOf("Mozilla/2") != -1 && agent.indexOf("Win") == -1) {
	    win = window.open(url, windowName , params);
	}

    if (win.opener == null) {
		win.opener = window;
	}
}

function openWindow(url,var_width,var_height,var_toolbar,var_location,var_directories,var_status,var_menubar,var_scrollbars,var_resizeable) {
	   
	agent = navigator.userAgent;
	windowName = "Console";
	
	params = "";
	params += "toolbar=";
	params += var_toolbar;
	params += ",location=";
	params += var_location;
	params += ",directories=";
	params += var_directories;
	params += ",status=";
	params += var_status;
	params += ",menubar=";
	params += var_menubar;
	params += ",scrollbars=";
	params += var_scrollbars;
	params += ",resizeable=";
	params += var_resizeable;
	params += ",width=";
	params += var_width;
	params += ",height=";
	params += var_height;
		  
	win = window.open(url, windowName , params);
	
	if (agent.indexOf("Mozilla/2") != -1 && agent.indexOf("Win") == -1) {
	        win = window.open(url, windowName , params);
	}
	   
	if (win.opener == null) {
	            win.opener = window;
	}
}

<!-- Creación de objeto imagen -->

imagen_mas=new Image
imagen_mas.src="../Images/mas01.gif"
imagen_menos=new Image
imagen_menos.src="../Images/menos01.gif"

<!-- Función para cambiar la imagen -->

function cambia_imagen(imagen)
{ 
if (document.images[imagen].src == imagen_mas.src)
{
document.images[imagen].src=imagen_menos.src;
}
else 
{
document.images[imagen].src=imagen_mas.src;
}
} 

function muestra_oculta(id){
if (document.getElementById){ //se obtiene el id
var el = document.getElementById(id); //se define la variable "el" igual a nuestro div
el.style.display = (el.style.display == 'none') ? 'block' : 'none'; //damos un atributo display:none que oculta el div
}
}