function roll(id){

   var objSrc = id.src;
   var ext = (objSrc.indexOf(".jpg") != -1) ? ".jpg" : ".gif";
   var idLength = objSrc.length;

   if(objSrc.indexOf("_over") != -1){
      var path = objSrc.substr(0, idLength - 9);
      id.src = path + ext;
   } else {
      var path = objSrc.substr(0, idLength - 4);
      id.src = path + "_over" + ext;
   }

}

function setSolution(id, num){
	for(var i=1; i<=num; i++){
		document.getElementById('solution' + i).style.display = "none";
	}

	document.getElementById('solution' + id).style.display = "block";
}

solution1 = new Image();
solution1.src = "images/solutions_nav1.gif";

solution2 = new Image();
solution2.src = "images/solutions_nav2.gif";

solution3 = new Image();
solution3.src = "images/solutions_nav3.gif";

solution4 = new Image();
solution4.src = "images/solutions_nav4.gif";

solution5 = new Image();
solution5.src = "images/solutions_nav5.gif";
	

function setNav(id){
	if(id != 0)document.images["solutions_nav"].src = "images/solutions_nav" + id + ".gif";
	else document.images["solutions_nav"].src = "images/solutions_nav.gif";
}