var cur_page = 1
var cur_screenshot = 1

// Left margins for browsers that work "correctly"
var news_text_left = 80
var about_text_left = 80
var screenshots_text_left = 13
var contact_text_left = 80
var demo_text_left = 80

var news_underline_left = 186
var about_underline_left = 288
var screenshots_underline_left = 395
var contact_underline_left = 564
var demo_underline_left = 688

var top_section_left = 0

// Preload images
imageNewsUnderline = new Image(64, 16)
imageNewsUnderline.src = "graphics/news_underline.png"

imageAboutUnderline = new Image(70, 16)
imageAboutUnderline.src = "graphics/about_underline.png"

imageScreenshotsUnderline = new Image(128, 16)
imageScreenshotsUnderline.src = "graphics/screenshots_underline.png"

imageContactUnderline = new Image(84, 16)
imageContactUnderline.src = "graphics/contact_underline.png"

imageDemoUnderline = new Image(88, 16)
imageDemoUnderline.src = "graphics/demo_underline.png"

// Text for each page
imageNewsText = new Image(624, 436)
imageNewsText.src = "graphics/news_text.png"

imageAboutText = new Image(580, 340)
imageAboutText.src = "graphics/about_text.png"

imageScreenshotsText = new Image(774, 104)
imageScreenshotsText.src = "graphics/screenshots_selector.jpg"

imageContactText = new Image(600, 500)
imageContactText.src = "graphics/contact_text.png"

imageDemoText = new Image(582, 496)
imageDemoText.src = "graphics/demo_text.png"

// The first, default screenshot
toolAreaScreenshot = new Image(776,420)
toolAreaScreenshot.src = "graphics/tool_area_screenshot.jpg"
		
function doSetUp() {
	if (useIE6Styles() == true) {
		// Fix left margins for things that we set dynamically
		news_text_left = -720;
		about_text_left = -720;
		screenshots_text_left = -787;
		contact_text_left = -720;
		demo_text_left = -720;
		
		news_underline_left = -614;
		about_underline_left = -512;
		screenshots_underline_left = -405;
		contact_underline_left = -236;
		demo_underline_left = -112;
	}
}

function useIE6Styles() {
	var ver = getInternetExplorerVersion();
	
	return ((ver > -1) && (ver < 8));
}

function getInternetExplorerVersion()
// Returns the version of Internet Explorer or a -1
// (indicating the use of another browser).
{
  var rv = -1; // Return value assumes failure.
  if (navigator.appName == 'Microsoft Internet Explorer')
  {
    var ua = navigator.userAgent;
    var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
    if (re.exec(ua) != null)
      rv = parseFloat( RegExp.$1 );
  }
  return rv;
}

function go(whichPageNumber) {
	cur_page = whichPageNumber
		
	if (cur_page == 1) {
		document.images[3].style.display="none"
		document.images[3].src = imageNewsText.src
		document.images[4].src = "graphics/blank.png"
		document.getElementById("main_body_image").style.marginLeft=news_text_left + "px"
		document.getElementById("main_body_image").style.top="204px"
		document.images[3].useMap="#newsmap"
		document.images[3].style.display=""
	} else if (cur_page == 2) {
		document.images[3].style.display="none"
		document.images[3].src = imageAboutText.src
		document.images[4].src = "graphics/blank.png"
		document.getElementById("main_body_image").style.marginLeft=about_text_left + "px"
		document.getElementById("main_body_image").style.top="204px"
		document.images[3].useMap=""
		document.images[3].style.display=""
	} else if (cur_page == 3) {
		document.images[3].style.display="none"
		document.images[3].src = imageScreenshotsText.src
		document.getElementById("main_body_image").style.marginLeft=screenshots_text_left + "px"
		document.getElementById("main_body_image").style.top="175px"
		document.images[3].useMap="#screenshotmap"
		setScreenshot(cur_screenshot)
		document.images[3].style.display=""
	} else if (cur_page == 4) {
		document.images[3].style.display="none"
		document.images[3].src = imageContactText.src
		document.images[4].src = "graphics/blank.png"
		document.getElementById("main_body_image").style.marginLeft=contact_text_left + "px"
		document.getElementById("main_body_image").style.top="184px"
		document.images[3].useMap="#contactmap"
		document.images[3].style.display=""
	} else {
		document.images[3].style.display="none"
		document.images[3].src = imageDemoText.src
		document.images[4].src = "graphics/blank.png"
		document.getElementById("main_body_image").style.marginLeft=demo_text_left + "px"
		document.getElementById("main_body_image").style.top="184px"
		document.images[3].useMap="#supportmap"
		document.images[3].style.display=""
	}
}

function hideUnderline() {
	document.images[2].src = "graphics/blank_underline.png"
}

function setScreenshot(whichScreenshot) {
	cur_screenshot = whichScreenshot
		
	if (cur_screenshot == 1) {
		document.images[4].src = toolAreaScreenshot.src
	} else if (cur_screenshot == 2) {
		document.images[4].src = "graphics/recruiting_screenshot.jpg"
	} else if (cur_screenshot == 3) {
		document.images[4].src = "graphics/sea_transport_screenshot.jpg"
	} else if (cur_screenshot == 4) {
		document.images[4].src = "graphics/syracuse_screenshot.jpg"
	} else if (cur_screenshot == 5) {
		document.images[4].src = "graphics/advise_senate_screenshot.jpg"
	} else if (cur_screenshot == 6) {
		document.images[4].src = "graphics/option_cards_screenshot.jpg"
	} else if (cur_screenshot == 7) {
		document.images[4].src = "graphics/pitched_battle_screenshot.jpg"
	} else {
		document.images[4].src = "graphics/sicily_screenshot.jpg"
	}	
}

function showUnderline(whichUnderline) {
	if (whichUnderline == 1) {
		document.images[2].src = imageNewsUnderline.src
		document.getElementById("page_marker").style.marginLeft= news_underline_left + "px"
	} else if (whichUnderline == 2) {
		document.images[2].src = imageAboutUnderline.src
		document.getElementById("page_marker").style.marginLeft= about_underline_left + "px"
	} else if (whichUnderline == 3) {
		document.images[2].src = imageScreenshotsUnderline.src
		document.getElementById("page_marker").style.marginLeft= screenshots_underline_left + "px"
	} else if (whichUnderline == 4) {
		document.images[2].src = imageContactUnderline.src
		document.getElementById("page_marker").style.marginLeft= contact_underline_left + "px"
	} else {
		document.images[2].src = imageDemoUnderline.src
		document.getElementById("page_marker").style.marginLeft= demo_underline_left + "px"
	}
}