/* 
   Originally from http://www.harrymaugans.com/2007/03/06/how-to-create-an-animated-sliding-collapsible-div-with-javascript-and-css/
 
   Update by Carbonize - http://carbonize.co.uk 
   Date: Sun, 10 March 2013 20:15:24 GMT
 
   To use simply use slidedown(objects ID) to slide it down/open or slideup(object ID) to make it slide up/closed
 
   Or simpler yet I have added toggleSlide(object ID) so you can just call one function and it will automatically slide the object 
   up or down depending on it's current situation
 
  Please remember to set the elements overflow to hidden as in overflow: hidden; otherwise it's contents will be visible.
 
  And you might want to add return: false; when you call it to stop the link you are using from doing anything.
*/
var timerlen = 5;
var slideAniLen = 250;
 
var timerID = new Array();
var startTime = new Array();
var obj = new Array();
var endHeight = new Array();
var moving = new Array();
var dir = new Array();
 
function slidedown(objname){
  if(moving[objname])
          return;
 
  if(document.getElementById(objname).style.display != "none")
          return; // cannot slide down something that is already visible
 
  moving[objname] = true;
  dir[objname] = "down";
  startslide(objname);
}
 
function slideup(objname){
  if(moving[objname])
          return;
 
  if(document.getElementById(objname).style.display == "none")
          return; // cannot slide up something that is already hidden
 
  moving[objname] = true;
  dir[objname] = "up";
  startslide(objname);
}
 
function startslide(objname){
  obj[objname] = document.getElementById(objname);
 
  startTime[objname] = (new Date()).getTime();
 
  if(dir[objname] == "down"){
          obj[objname].style.height = "1px";
  }
 
  obj[objname].style.display = "block";
  endHeight[objname] = parseInt(obj[objname].scrollHeight);
 
  timerID[objname] = setInterval('slidetick(\'' + objname + '\');',timerlen);
}
 
function slidetick(objname){
  var elapsed = (new Date()).getTime() - startTime[objname];
 
  if (elapsed > slideAniLen)
          endSlide(objname)
  else {
          var d =Math.round(elapsed / slideAniLen * endHeight[objname]);
          if(dir[objname] == "up")
                  d = endHeight[objname] - d;
 
          obj[objname].style.height = d + "px";
  }
 
  return;
}
 
function endSlide(objname){
  clearInterval(timerID[objname]);
 
  if(dir[objname] == "up")
          obj[objname].style.display = "none";
 
  obj[objname].style.height = endHeight[objname] + "px";
 
  delete(moving[objname]);
  delete(timerID[objname]);
  delete(startTime[objname]);
  delete(endHeight[objname]);
  delete(obj[objname]);
  delete(dir[objname]);
 
  return;
}
 
function toggleSlide(objname) {
  // Pointless going any further if we are already sliding the object
  if(moving[objname])
          return;
  if (document.getElementById(objname).style.display == 'none') {
    // div is hidden, so let's slide down
    slidedown(objname);
  } else {
    // div is not hidden, so slide up
    slideup(objname);
  }
}

<a onclick="toggleSlide('myDiv'); return false;" href="somewhere.php">Toggle Div</a>

function randomString($strLen = 32)
{
  // Create our character arrays
  $chrs = array_merge(range('a', 'z'), range('A', 'Z'), range(0, 9));
 
  // Just to make the output even more random
  shuffle($chrs);
 
  // Create a holder for our string
  $randStr = '';
 
  // Now loop through the desired number of characters for our string
  for($i=0; $i<$strLen; $i++)
  {
    $randStr .= $chrs[mt_rand(0, (count($chrs) - 1))];
  }
  return $randStr;
}

function randomString(len) {
  // Just an array of the characters we want in our random string
  var chrs = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
              'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
              '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
 
  // Check that a length has been supplied and if not default to 32
  len = (isNaN(len)) ? 32 : len;
 
  // The following section shuffles the array just to further randomise the output
  var tmp, current, top = chrs.length; 
  if(top)
  {
    while(--top) 
    { 
      current = Math.floor(Math.random() * (top + 1)); 
      tmp = chrs[current]; 
      chrs[current] = chrs[top]; 
      chrs[top] = tmp; 
    }
  }
 
  // Just a holder for our random string
  var randomStr = '';
 
  // Loop through the required number of characters grabbing one at random from the array each time
  for(i=0;i<len;i++) 
  {
    randomStr = randomStr + chrs[Math.floor(Math.random()*chrs.length)];
  }
 
  // Return our random string
  return randomStr;
}

<img src="http://domain.com/path/image.jpg" name="NAMEFORIMAGE" alt="" />

<a href="#" onclick="reloadImage('NAMEFORIMAGE'); return false;">request another image</a>

function reloadImage(imageName)
{
var myImages=new Array();
myImages[0]="sun.jpg";
myImages[1]="moon.jpg";
myImages[2]="stars.jpg";
// Create a random number between 1 and one greater than the number of items in the array
var randomImage = Math.floor(Math.random() * (myImages.length + 1));
randomImage--;
// Change the image
document.images[imageName].src = 'http://yoursite.com/path/to/' + myImages[randomImage];
}

function reloadImage(imageName)
{
// Create a random number between 1 and 1000
var randomnumber=Math.floor(Math.random()*1001);
// Change the image
document.images[imageName].src = 'http://yoursite.com/path/image.php?hash=OURHASH&rand=' + randomnumber;
}

document.images[imageName].src = document.images[imageName].src + '&rand=' + randomnumber; // Change the image