function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}

function MM_jumpMenu(targ,selObj,restore){ //v3.0
  eval(targ+".location='"+selObj.options[selObj.selectedIndex].value+"'");
  if (restore) selObj.selectedIndex=0;
}

function enewsletter_Validator(theForm)
{

  if (theForm.address_email.value == "")
  {
    alert("Please enter a value for the \"Email\" field.");
    theForm.address_email.focus();
    return (false);
  }

  if ((theForm.address_email.value.indexOf('@',0) == -1) || (theForm.address_email.value.indexOf('.',0) == -1))
  {
    alert("Please verify that the value for the \"Email\" field is valid.");
    theForm.address_email.focus();
    return (false);
  }
  return (true);
}

function pop(url) {
  link = window.open(url,"pop","toolbar=0,location=0,directories=0,status=1,menubar=0,scrollbars=1,resizable=1,width=640,height=480,left=25,top=25");
}

function closeWindow() {
  window.close()
}

function tellafriend_Validator(theForm)
{

  if (theForm.your_name.value == "")
  {
    alert("Please enter your name.");
    theForm.your_name.focus();
    return (false);
  }

  if (theForm.your_email.value == "")
  {
    alert("Please enter your email address.");
    theForm.your_email.focus();
    return (false);
  }

  if ((theForm.your_email.value.indexOf('@',0) == -1) || (theForm.your_email.value.indexOf('.',0) == -1))
  {
    alert("Your email address is incorrectly formatted. Please enter again.");
    theForm.your_email.focus();
    return (false);
  }

  if (theForm.friends_name.value == "")
  {
    alert("Please enter your friend's name.");
    theForm.friends_name.focus();
    return (false);
  }

  if (theForm.friends_email.value == "")
  {
    alert("Please enter your friend's email address.");
    theForm.friends_email.focus();
    return (false);
  }

  if ((theForm.friends_email.value.indexOf('@',0) == -1) || (theForm.friends_email.value.indexOf('.',0) == -1))
  {
    alert("Friend's email address is incorrectly formatted. Please enter again.");
    theForm.friends_email.focus();
    return (false);
  }

  return (true);
}
// =================================
// Drop-Down Menu for IE
// =================================
sfHover = function() {
	var sfEls = document.getElementById("nav").getElementsByTagName("LI");
	for (var i=0; i<sfEls.length; i++) {
		sfEls[i].onmouseover=function() {
			this.className+=" sfhover";
		}
		sfEls[i].onmouseout=function() {
			this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
		}
	}
}
if (window.attachEvent) window.attachEvent("onload", sfHover);



<!-- WELCOME PAGE IMAGE ROTATOR
// ==============================================
// Copyright 2003 by jsCode.com
// Source: jsCode.com
// Author: etLux
// Free for all; but please leave in the header.
// ==============================================

// Set up the image files to be used.
var theImages = new Array() // do not change this
// To add more image files, continue with the
// pattern below, adding to the array. Rememeber
// to increment the theImages[x] index!

theImages[0] = 'http://dev.aerobiology.net/images/header_photo/welcome/001.jpg'
theImages[1] = 'http://dev.aerobiology.net/images/header_photo/welcome/002.jpg'
theImages[2] = 'http://dev.aerobiology.net/images/header_photo/welcome/003.jpg'
theImages[3] = 'http://dev.aerobiology.net/images/header_photo/welcome/004.jpg'
theImages[4] = 'http://dev.aerobiology.net/images/header_photo/welcome/005.jpg'
theImages[5] = 'http://dev.aerobiology.net/images/header_photo/welcome/006.jpg'
theImages[6] = 'http://dev.aerobiology.net/images/header_photo/welcome/007.jpg'
theImages[7] = 'http://dev.aerobiology.net/images/header_photo/welcome/008.jpg'
theImages[8] = 'http://dev.aerobiology.net/images/header_photo/welcome/009.jpg'
theImages[9] = 'http://dev.aerobiology.net/images/header_photo/welcome/010.jpg'
theImages[10] = 'http://dev.aerobiology.net/images/header_photo/welcome/011.jpg'
theImages[11] = 'http://dev.aerobiology.net/images/header_photo/welcome/012.jpg'
theImages[12] = 'http://dev.aerobiology.net/images/header_photo/welcome/013.jpg'
theImages[13] = 'http://dev.aerobiology.net/images/header_photo/welcome/014.jpg'
theImages[14] = 'http://dev.aerobiology.net/images/header_photo/welcome/015.jpg'
theImages[15] = 'http://dev.aerobiology.net/images/header_photo/welcome/016.jpg'
theImages[16] = 'http://dev.aerobiology.net/images/header_photo/welcome/017.jpg'
theImages[17] = 'http://dev.aerobiology.net/images/header_photo/welcome/018.jpg'
theImages[18] = 'http://dev.aerobiology.net/images/header_photo/welcome/019.jpg'
theImages[19] = 'http://dev.aerobiology.net/images/header_photo/welcome/020.jpg'


// ======================================
// do not change anything below this line
// ======================================

var j = 0
var p = theImages.length;

var preBuffer = new Array()
for (i = 0; i < p; i++){
   preBuffer[i] = new Image()
   preBuffer[i].src = theImages[i]
}

var whichImage = Math.round(Math.random()*(p-1));
function showImage(){
document.write('<img src="'+theImages[whichImage]+'">');
}
//-->

<!-- INTERIOR PAGE IMAGE ROTATOR
// ==============================================
// Copyright 2003 by jsCode.com
// Source: jsCode.com
// Author: etLux
// Free for all; but please leave in the header.
// ==============================================

// Set up the image files to be used.
var theInteriorImages = new Array() // do not change this
// To add more image files, continue with the
// pattern below, adding to the array. Rememeber
// to increment the theImages[x] index!

theInteriorImages[0] = 'http://dev.aerobiology.net/images/header_photo/interior/001.jpg'
theInteriorImages[1] = 'http://dev.aerobiology.net/images/header_photo/interior/002.jpg'
theInteriorImages[2] = 'http://dev.aerobiology.net/images/header_photo/interior/003.jpg'
theInteriorImages[3] = 'http://dev.aerobiology.net/images/header_photo/interior/004.jpg'
theInteriorImages[4] = 'http://dev.aerobiology.net/images/header_photo/interior/005.jpg'
theInteriorImages[5] = 'http://dev.aerobiology.net/images/header_photo/interior/006.jpg'
theInteriorImages[6] = 'http://dev.aerobiology.net/images/header_photo/interior/007.jpg'
theInteriorImages[7] = 'http://dev.aerobiology.net/images/header_photo/interior/008.jpg'
theInteriorImages[8] = 'http://dev.aerobiology.net/images/header_photo/interior/009.jpg'
theInteriorImages[9] = 'http://dev.aerobiology.net/images/header_photo/interior/010.jpg'
theInteriorImages[10] = 'http://dev.aerobiology.net/images/header_photo/interior/011.jpg'
theInteriorImages[11] = 'http://dev.aerobiology.net/images/header_photo/interior/012.jpg'
theInteriorImages[12] = 'http://dev.aerobiology.net/images/header_photo/interior/013.jpg'
theInteriorImages[13] = 'http://dev.aerobiology.net/images/header_photo/interior/014.jpg'
theInteriorImages[14] = 'http://dev.aerobiology.net/images/header_photo/interior/015.jpg'
theInteriorImages[15] = 'http://dev.aerobiology.net/images/header_photo/interior/016.jpg'
theInteriorImages[16] = 'http://dev.aerobiology.net/images/header_photo/interior/017.jpg'
theInteriorImages[17] = 'http://dev.aerobiology.net/images/header_photo/interior/018.jpg'
theInteriorImages[18] = 'http://dev.aerobiology.net/images/header_photo/interior/019.jpg'
theInteriorImages[19] = 'http://dev.aerobiology.net/images/header_photo/interior/020.jpg'
theInteriorImages[20] = 'http://dev.aerobiology.net/images/header_photo/interior/021.jpg'
theInteriorImages[21] = 'http://dev.aerobiology.net/images/header_photo/interior/022.jpg'
theInteriorImages[22] = 'http://dev.aerobiology.net/images/header_photo/interior/023.jpg'
theInteriorImages[23] = 'http://dev.aerobiology.net/images/header_photo/interior/024.jpg'
theInteriorImages[24] = 'http://dev.aerobiology.net/images/header_photo/interior/025.jpg'
theInteriorImages[25] = 'http://dev.aerobiology.net/images/header_photo/interior/026.jpg'
theInteriorImages[26] = 'http://dev.aerobiology.net/images/header_photo/interior/027.jpg'
theInteriorImages[27] = 'http://dev.aerobiology.net/images/header_photo/interior/028.jpg'
theInteriorImages[28] = 'http://dev.aerobiology.net/images/header_photo/interior/029.jpg'
theInteriorImages[29] = 'http://dev.aerobiology.net/images/header_photo/interior/030.jpg'
theInteriorImages[30] = 'http://dev.aerobiology.net/images/header_photo/interior/031.jpg'
theInteriorImages[31] = 'http://dev.aerobiology.net/images/header_photo/interior/032.jpg'
theInteriorImages[32] = 'http://dev.aerobiology.net/images/header_photo/interior/033.jpg'
theInteriorImages[33] = 'http://dev.aerobiology.net/images/header_photo/interior/034.jpg'
theInteriorImages[34] = 'http://dev.aerobiology.net/images/header_photo/interior/035.jpg'
theInteriorImages[35] = 'http://dev.aerobiology.net/images/header_photo/interior/036.jpg'
theInteriorImages[36] = 'http://dev.aerobiology.net/images/header_photo/interior/037.jpg'
theInteriorImages[37] = 'http://dev.aerobiology.net/images/header_photo/interior/038.jpg'
theInteriorImages[38] = 'http://dev.aerobiology.net/images/header_photo/interior/039.jpg'
theInteriorImages[39] = 'http://dev.aerobiology.net/images/header_photo/interior/040.jpg'

// ======================================
// do not change anything below this line
// ======================================

var j = 0
var p = theInteriorImages.length;

var preIntBuffer = new Array()
for (i = 0; i < p; i++){
   preIntBuffer[i] = new Image()
   preIntBuffer[i].src = theInteriorImages[i]
}

var whichIntImage = Math.round(Math.random()*(p-1));
function showInteriorImage(){
document.write('<img src="'+theInteriorImages[whichIntImage]+'">');
}
//-->