function flip(thumb, big) {
  var b = new Array();
  var tmp;

  if (thumb.src.indexOf('backview') >= 0) {
    b = thumb.src.split('backview');
    thumb.src = b[0] + 'view' + b[1];
    b = big.src.split('view');
    big.src = b[0] + 'backview' + b[1];
  } else if (thumb.src.indexOf('view') >= 0) {
    b = thumb.src.split('view');
    thumb.src = b[0] + 'backview' + b[1];
    b = big.src.split('backview');
    big.src = b[0] + 'view' + b[1];
  } else {
    tmp = big.src;
    big.src = thumb.src;
    thumb.src = tmp;
  }
}

function blowup(what, e) {
  if (!e) var e = window.event;

  if (typeof e.pageX == 'number') {
    y = e.pageY;
  } else {
    if (document.documentElement && document.documentElement.scrollTop) {
      y = e.clientY + document.documentElement.scrollTop;
    } else {
      y = e.clientY + document.body.scrollTop;
    }
  }

  ptop = y-300;

  src = document.getElementById(what);
  div = document.getElementById('enlarged_div');
  tgt = document.getElementById('enlarged_img');

  tgt.src = src.src.replace(/118|335|400|500/, '700');
  div.style.top = ptop + 'px';
  grayOut(true);
  div.style.display = 'inline';
}

function toggleDiv(divID) {
  thediv = document.getElementById(divID);
  if (thediv.style.display == 'none') {
    thediv.style.display = 'block';
  } else {
    thediv.style.display = 'none';
  }
}

function grayOut(vis, options) {
  // Pass true to gray out screen, false to ungray
  // options are optional.  This is a JSON object with the following (optional) properties
  // opacity:0-100         // Lower number = less grayout higher = more of a blackout 
  // zindex: #             // HTML elements with a higher zindex appear on top of the gray out
  // bgcolor: (#xxxxxx)    // Standard RGB Hex color code
  // grayOut(true, {'zindex':'50', 'bgcolor':'#0000FF', 'opacity':'70'});
  // Because options is JSON opacity/zindex/bgcolor are all optional and can appear
  // in any order.  Pass only the properties you need to set.
  var options = options || {}; 
  var zindex = options.zindex || 50;
  var opacity = options.opacity || 70;
  var opaque = (opacity / 100);
  var bgcolor = options.bgcolor || '#000000';
  var dark=document.getElementById('darkenScreenObject');
  if (!dark) {
    // The dark layer doesn't exist, it's never been created.  So we'll
    // create it here and apply some basic styles.
    // If you are getting errors in IE see: http://support.microsoft.com/default.aspx/kb/927917
    var tbody = document.getElementsByTagName("body")[0];
    var tnode = document.createElement('div');           // Create the layer.
        tnode.style.position='absolute';                 // Position absolutely
        tnode.style.top='0px';                           // In the top
        tnode.style.left='0px';                          // Left corner of the page
        tnode.style.overflow='hidden';                   // Try to avoid making scroll bars            
        tnode.style.display='none';                      // Start out Hidden
        tnode.id='darkenScreenObject';                   // Name it so we can find it later
    tbody.appendChild(tnode);                            // Add it to the web page
    dark=document.getElementById('darkenScreenObject');  // Get the object.
  }
  if (vis) {
    // Calculate the page width and height 
    if( document.body && ( document.body.scrollWidth || document.body.scrollHeight ) ) {
        var pageWidth = document.body.scrollWidth+'px';
        var pageHeight = document.body.scrollHeight+'px';
    } else if( document.body.offsetWidth ) {
      var pageWidth = document.body.offsetWidth+'px';
      var pageHeight = document.body.offsetHeight+'px';
    } else {
       var pageWidth='100%';
       var pageHeight='100%';
    }   
    //set the shader to cover the entire page and make it visible.
    dark.style.opacity=opaque;                      
    dark.style.MozOpacity=opaque;                   
    dark.style.filter='alpha(opacity='+opacity+')'; 
    dark.style.zIndex=zindex;        
    dark.style.backgroundColor=bgcolor;  
    dark.style.width= pageWidth;
    dark.style.height= pageHeight;
    dark.style.display='block';                          
  } else {
     dark.style.display='none';
  }
}