function popup(mylink, windowname)
{
if (! window.focus)return true;
var href;
if (typeof(mylink) == 'string')
   href=mylink;
else
   href=mylink.href;
window.open(href, windowname, 'width=500,height=500,left=700,top=200,scrollbars=yes');
return false;
}
function adjustStyle(width) {
    width = parseInt(width);
    if ((width >= 800) && (width < 1024))
	{
        $("#size-stylesheet").attr("href", "style_vietnam_medium_small.css");
	} 
	else 
	{
       $("#size-stylesheet").attr("href", "style_vietnam_large.css");
	}
}
$(function() {
    adjustStyle($(this).width());
    $(window).resize(function() {
        adjustStyle($(this).width());
    });
});