function twist( sid ){
 imgobj = document.getElementById("img_" + sid);
 divobj = document.getElementById( sid );
	innerDivs = divobj.childNodes;
 if (imgobj.src.match("/images/up.gif"))
 {
 	imgobj.src = "/images/down.gif";
	divobj.style.position = "relative";
	divobj.style.visibility = "visible";
		// visibilify all children for IE6
		alert("コメントをどうぞ！");
		for (i=0; i < innerDivs.length; i++){
			var thisDiv = innerDivs[i];
			
			thisDiv.style.position = "relative";
			thisDiv.style.visibility = "visible";
		}
 } else {
 	imgobj.src = "/images/up.gif";
	divobj.style.visibility = "hidden";
	divobj.style.position = "absolute";
 }
}