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_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_findObj(n, d) { //v4.0
  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 && document.getElementById) x=document.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];}
}

var img_seq=new Array();
var img_stack=new Array();
var img_obj=new Array();
var img_stack_idx=0;
function swap_img(img_id,img_src){
obj=document.getElementById(img_id);if(obj){obj.src=img_src;}
}

function load_img(img_src){
img=new Image();img.src=img_src;
}
function on_load(){
	load_img('images/a2.gif');
	load_img('images/c2.gif');
	load_img('images/m2.gif');
	load_img('images/wbc2.gif');
	load_img('images/utsla2.gif');
	load_img('images/b2.gif');
	load_img('images/cl2.gif');

    img_seq[0]=1;
    img_seq[1]=1;
    img_seq[2]=1;
    img_seq[3]=1;
    
    img_stack[0]=0;
    img_stack[1]=1;
    img_stack[2]=2;
    img_stack[3]=3;
    
    for(x=0;x<4;++x)
        img_obj[x]=document.getElementById('img_rot_'+x);
    
    img_stack_idx=0;
    
    shuffle_img_stack();
    setTimeout('rotate_imgs()',Math.round(Math.random()*2000)+2000);
}

function shuffle_img_stack()
{
    for(i=0;i<img_stack.length;++i)
    {
        idx1=i;
        idx2=Math.round(Math.random()*(img_stack.length-1));
        
        t=img_stack[idx2];
        img_stack[idx2]=img_stack[idx1];
        img_stack[idx1]=t;
    }
}
function rotate_imgs()
{
    col=img_stack[img_stack_idx];
    if(img_obj[col])
    {
        ++img_seq[col];
        if(col==0 && img_seq[col]>10) img_seq[col]=1;
        if(col==1 && img_seq[col]>7) img_seq[col]=1;
        if(col==2 && img_seq[col]>11) img_seq[col]=1;
        if(col==3 && img_seq[col]>7) img_seq[col]=1;
        
        img_obj[col].src='../rotating_images/img_'+col+'_'+img_seq[col]+'.jpg';
    }
    
    ++img_stack_idx;
    if(img_stack_idx>=img_stack.length)
    {
        img_stack_idx=0;
        shuffle_img_stack();
    }

    setTimeout('rotate_imgs()',Math.round(Math.random()*2000)+2000);
}

on_load();