// copyright 2002 hesketh.com/inc. all rights reserved
var currentSlide = 0;
var lastSlide = 20;

function hide(what) {
 var a;
 if(document.getElementById) {
  a = document.getElementById(what);
 } else {
  a = eval("document."+what);
 }
 a.style["visibility"] = "hidden";
}

function show(what) {
 var a;
 if(document.getElementById) {
  a = document.getElementById(what);
 } else {
  a = eval("document."+what);
 }
 a.style["visibility"] = "visible";
}

function set_current_location() {
 var c;
 if(document.getElementById) {
  c = document.getElementById("currentlocation");
 } else {
  c = document.currentlocation;
 }
 c.innerHTML = "slide "+currentSlide+" of "+lastSlide;
 if(currentSlide > 0) {
  c.style["visibility"] = "visible";
 } else {
  c.style["visibility"] = "hidden";
 }
}

function flip(which) {
 if((which == "next") && (currentSlide < lastSlide)) {
  hide("slide"+currentSlide);
  if(currentSlide == 0) {
    hide("navnexttitle");
    show("navprev");
    show("navnext");
  } else if(currentSlide == (lastSlide -1)) {
    show("navprev");
    hide("navnext");
  }
  show("slide"+(++currentSlide));
 } else if((which == "prev") && (currentSlide > 0)) {
  hide("slide"+currentSlide);
  if(currentSlide == 1) {
    show("navnexttitle");
    hide("navprev");
    hide("navnext");
  } else if(currentSlide <= lastSlide) {
    show("navprev");
    show("navnext");
  }
  show("slide"+(--currentSlide));
 }
 set_current_location();
}

var imgdir              = '/publications/value_of_standards_for_web_design/img/';
var nextarrow           = 'navclicknext-20x20.gif';
var nextarrowhover      = 'navclicknext-hover-20x20.gif';
var prevarrow           = 'navclickprev-20x20.gif';
var prevarrowhover      = 'navclickprev-hover-20x20.gif';
var transnextarrow      = 'navclicknext-trans-20x20.gif';
var transnextarrowhover = 'navclicknext-hover-t-20x20.gif';

function hover_on(which) {
 if(document.getElementById) {
  var i = document.getElementById(which+"arrow");
  i.setAttribute("src", imgdir+eval(which+"arrowhover"));
 } else {
  var i = eval("document."+which+"arrow.src = "+which+"arrowhover");
 }
}

function hover_off(which) {
 if(document.getElementById) {
  var i = document.getElementById(which+"arrow");
  i.setAttribute("src", imgdir+eval(which+"arrow"));
 } else {
  var i = eval("document."+which+"arrow.src = "+which+"arrow");
 }
}