// global variables ---------------------------------------------

var browser;			// browser variable
var layerRef, styleSwitch;	// browser difference vars
var jump = 10;			// window scrolling speed
var miliwait = 20; 		// miliseconds to wait between scroll loops
var scrolling = 0;

// functions ------------------------------------------------------

// browser detect
function browser_detect() {
  if(document.layers) browser="NS4";
  else if(document.all) browser="IE4";
  else if(document.getElementById) browser="DOM2";
  else browser="DOM2";		
  if(browser=="NS4") {
    layerRef="document.layers";
    styleSwitch="";
  }
  if(browser=="IE4") {
    layerRef="document.all";
    styleSwitch=".style";
  }
  if(browser=="DOM2") {		// ns6 or ie5
    layerRef="document.getElementById";
    styleSwitch=".style";  
    jump=10;			// ns6 is slow as hell
  }
  if((browser=="NS4") || (browser=="DOM2")) {    // unix? slow scroll
    var agent = navigator.userAgent.toLowerCase();
    if(agent.indexOf("x11") != -1) {
      if(browser=="DOM2") jump=10; 
      else jump=3;
    }
  }
}	

// clip a layer
function clipLayer(myLayer,top,right,bottom,left) {
  if(browser=="NS4") {
    eval('document.layers["'+myLayer+'"].clip.top='+top);
    eval('document.layers["'+myLayer+'"].clip.right='+right);
    eval('document.layers["'+myLayer+'"].clip.bottom='+bottom);
    eval('document.layers["'+myLayer+'"].clip.left='+left);
  }
  else if(browser=="IE4")
    document.all[myLayer].style.clip='rect('+top+' '+right+' '+bottom+' '+left+')';
  else if(browser=="DOM2") {
    document.getElementById(myLayer).style.clip='rect('+top+' '+right+' '+bottom+' '+left+')';
  }
}

// show a layer
function showLayer(myLayer) {
  if(browser=="DOM2")
    eval(layerRef+'("'+myLayer+'")'+styleSwitch+'.visibility="visible"');
  else 
    eval(layerRef+'["'+myLayer+'"]'+styleSwitch+'.visibility="visible"');
}

// hide a layer
function hideLayer(myLayer) {
  if(browser=="DOM2")
    eval(layerRef+'("'+myLayer+'")'+styleSwitch+'.visibility="hidden"');
  else
    eval(layerRef+'["'+myLayer+'"]'+styleSwitch+'.visibility="hidden"');
}

// set page top of layer
function setTopLayer(myLayer,where) {
  if(browser=="DOM2")
    eval(layerRef+'("'+myLayer+'")'+styleSwitch+'.top='+where);
  else
    eval(layerRef+'["'+myLayer+'"]'+styleSwitch+'.top='+where);
}

// get page top of layer

function getTopLayer(myLayer) {
  if(browser=="NS4")
    return(eval(layerRef+'["'+myLayer+'"].pageY'));
  if(browser=="IE4")
    return(eval(layerRef+'["'+myLayer+'"].offsetTop'));
  if(browser=="DOM2")
    return(eval(layerRef+'("'+myLayer+'").offsetTop'));
}
    	
// get height of a layer
function getHeightLayer(myLayer) {
  if(browser=="NS4") {
    if(dh = eval(layerRef+'["'+myLayer+'"].document.height')) return(dh); 
    else {
      clipbottom = eval(layerRef+'["'+myLayer+'"].clip.bottom')
      cliptop = eval(layerRef+'["'+myLayer+'"].clip.top')
      return(clipbottom - cliptop);
    }
  }
  if(browser=="IE4") {
    if(dh = eval(layerRef+'["'+myLayer+'"]'+styleSwitch+'.pixelHeight')) return(dh);
    else return(eval(layerRef+'["'+myLayer+'"].clientHeight'));
  }
  if(browser=="DOM2")
    return(eval(layerRef+'("'+myLayer+'").offsetHeight'));
}

function scrollDn(myLayer) {
	if(scrolling) {
		var count = getTopLayer(myLayer);
		if(count < 0) {
			if(count < (0 - jump)) { count += jump; }
			else { count = 0; }
			setTopLayer(myLayer, count);
		} else {
			scrolling = 0;
		}
		setTimeout('scrollDn("'+myLayer+'")', miliwait);
	}
}

function scrollUp(myLayer) {
	if(scrolling) {
		var count = getTopLayer(myLayer);
		if(count > -400) {
			count -= jump;
			setTopLayer(myLayer, count);
			scrolling = 1;
		} else {
			scrolling = 0;
		}
		setTimeout('scrollUp("'+myLayer+'")', miliwait);
	}
}

function scrollDown(myLayer) {
	scrolling = 1;
	scrollDn(myLayer);
}

function scrollBack(myLayer) {
	scrolling = 1;
	scrollUp(myLayer);
}

function scroll(myLayer) {
	var count = getTopLayer(myLayer);
	if(count <= -400) { scrollDown(myLayer); }
	if(count >= 0) { scrollBack(myLayer); } }

// init function
function sliderStartup() {
  // find out what browser they're using and set global vars
  browser_detect();

  // show the slider
  showLayer('slider');
  scrollDown('slider');
  //setTimeout("scrollBack('slider')", 8000);
 }
function sliderClose()
{
	scrollBack('slider');
}