var large_width=200;
var small_width=100;
var direction;
var i, j=1,n=5, timeout=10;

function slidelarge(image){
  i=image;
  direction=1;
  rs();
}

function slidesmall(image){
  direction=-1;
  rs();
}

function xy(x1,x2,j)
{
  return (x2-x1)*j/n+x1;
}

function rs()
{
  i.style.width = xy(small_width, large_width, j);
  
  if(direction > 0 && n > j){
   j++;
   setTimeout('rs()', timeout);
  }
  else { 
  
    if(direction < 0 && j > 0){
     j--;
	 setTimeout('rs()', timeout);
    }
  }
}