function check_progress (base_url, token, to, pwidth)
{
	poll_token(base_url, token, to, pwidth);
}

function poll_token (base_url, token, to, pwidth)
{
	var a = new Ajax.Request ( base_url + '/progress/get?token=' + token,
	{
		method: 'get', 
		onSuccess: function(t)
		{
			var s     = t.responseText.toString();
			
			if ( s.search(/^(\d+\.\d+)\t(.+)/) > -1 )
			{
				var a = s.match( /^(\d+\.\d+)\t(.+)/ );

				var prozent = a[1];
				var meldung = a[2];
				
				var p = 1 / (100/prozent);
				
				if ( pwidth == null )
				{
					pwidth='200';
				}
				
				var l = pwidth * p;
				var r = pwidth * (1 - p);

				$(to + '_label').innerHTML = meldung + "( " + prozent + "% )";
				$(to + '_done').style.width = l.numberFormat('#') + "px";
				$(to + '_left').style.width = r.numberFormat('#') + "px";

				var f = function () { poll_token(base_url,token,to, pwidth); };
				setTimeout(f,500);
			}
			else
			{
				if ( s.search(/^ok/i) > -1 )
				{

					$(to + '_done').style.width = pwidth + "px";
					$(to + '_done').style.background = 'green';
					$(to + '_label').style.color = 'green';
					$(to + '_label').innerHTML = "abgeschlossen ( 100% )";

					$(to + '_left').style.width = "0px";

					$(to + '_ok').style.display = 'inline';
	
					return true;
				}
				
				if ( s.search(/^error/i) > -1)
				{
					$(to + '_done').style.background = 'red';
					$(to + '_label').style.color = 'red';
					
					$(to + '_error').style.display = 'inline';
					
					return false;
				}
				
				var f = function () { poll_token(base_url,token,to, pwidth); };
				setTimeout(f,500);
			}
		}, 

		onFailure:function(t)
		{
			alert('Fehler beim Zugriff auf Webserver: ' + t.status + ' -- ' + t.statusText);
		}, 
		asynchronous:!check_sync
	});
}