function upDateMainSection(src1, src2){
	changeMainImg(src1);
     var btnbefore = document.getElementById("btn_before");
     	btnbefore.href="javascript:changeMainImg('"+src2+"')";
     var btnafter = document.getElementById("btn_after");
     	btnafter.href="javascript:changeMainImg('"+src1+"')";
}

function changeMainImg(src){
		var mimg = document.getElementById("cur_main_img");
		$("#cur_main_img").fadeTo(700, 0, function(){mimg.src = src;});
		$("#cur_main_img").fadeTo(700, 1.0);
}