var im1 = new Image();
im1.src = "images/anim1.jpg";
var im2 = new Image();
im2.src = "images/anim2.jpg";
var im3 = new Image();
im3.src = "images/anim3.jpg";
var im4 = new Image();
im4.src = "images/anim4.jpg";

function startanim(){		
 if(document.getElementById('animimage')==null){     
   return false;     
 }          
 window.setInterval("animate()",6000);     		
}
		
function animate(){	        
  var anim=document.getElementById('animimage');    
  if(anim.src==im1.src) {       
       document.images["animimage"].src=im2.src;
  } else if (anim.src==im2.src) {
       document.images["animimage"].src=im3.src;
  } else if(anim.src==im3.src) {
       document.images["animimage"].src=im4.src;
  } else if(anim.src=im4.src){
       document.images["animimage"].src=im1.src;
  }		
}