function perform(URL, target, vars) {
  var php;
  try { php=new XMLHttpRequest(); }
  catch (e) {
    try { php=new ActiveXObject("Msxml2.XMLHTTP"); }
    catch (e) {
      try { php=new ActiveXObject("Microsoft.XMLHTTP"); }
      catch (e) {
        alert("Your browser does not support AJAX.\n\nPlease use a compatible browser (examples: Firefox or IE6+)");
        return false;
      }
    }
  }
	document.getElementById(target).innerHTML='Loading content...';
	php.onreadystatechange=function() {
		if(php.readyState==4) {
			document.getElementById(target).innerHTML=php.responseText;
		}		
  }

	php.open("POST",URL,true);
	php.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	php.send(vars);
}

function comment(item, id) {
	var obj=document.getElementById('postcomment'+id);
	if (item.innerHTML=='post comment') {
		item.innerHTML='cancel';
		obj.style.display='block';
	}
	else {
		item.innerHTML='post comment';
		obj.style.display='none';
	}
}