function echeck(str,empty)  //email check ; empty - czy moze byc pusty
{
var at="@";
var dot=".";
var lat=str.indexOf(at);
var lstr=str.length;
var ldot=str.indexOf(dot);

if ((empty)&&(lstr==0)) return true;	
if (str.indexOf(at)==-1) return false;		   		
if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr) return false;
if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr) return false;
if (str.indexOf(at,(lat+1))!=-1) return false;
if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot) return false;
if (str.indexOf(dot,(lat+2))==-1) return false;
if (str.indexOf(" ")!=-1) return false;
return true;					
}
//************************************************************************
function ShowImageLayer(filename, title) //klikniecie na obrazek zamyka okno
{
	var border_width='4px';	
	var background_color='#8D7A6B'; 
	
	container=document.getElementById('img_layer_div'); 
	preloader=document.getElementById('img_preloader_layer_div'); 
	preloader.style.display='block';	
	preloader.style.left=parseInt((document.documentElement.clientWidth-preloader.offsetWidth)/2)+document.documentElement.scrollLeft+'px';
	preloader.style.top=parseInt((document.documentElement.clientHeight-preloader.offsetHeight)/2)+document.documentElement.scrollTop+'px';
	container.style.display='none';				
		
	advAJAX.get({
		url: '/php/img_params.php?filename='+filename,
		onSuccess : function(obj) 
		{
			//jeśli odpowiedź to komunikat błędu dłuższy niż string 1234|1234 (+zapas)
			if (obj.responseText.length>20) { preloader.style.display='none'; return; }
			pos=obj.responseText.indexOf('|');
			image_width=obj.responseText.substr(0,pos);
			image_height=obj.responseText.substr(pos+1);
			container.innerHTML='<a href="javascript:HideImageLayer()" title="Kliknij, aby zamknąć obraz." border="0"><img src="'+filename+'" width="'+image_width+'" height="'+image_height+'" alt="Kliknij, aby zamknąć obraz." border="0" style="margin:0; border:'+border_width+' solid '+background_color+';" onload="preloader.style.display=\'none\'"></a>';		
			container.style.display='block';						
			image_left=parseInt((document.documentElement.clientWidth-container.offsetWidth)/2);
			if (image_left<0) image_left=0;	
			image_top=parseInt((document.documentElement.clientHeight-container.offsetHeight)/2);
			if (image_top<0) image_top=0;
 			image_top+=document.documentElement.scrollTop;		 
			container.style.top=image_top+'px';
			container.style.left=image_left+'px';				
		},
	   mimeType: 'text/plain'
	});	

}
//************************************************************************
function HideImageLayer()
{
   document.getElementById('img_layer_div').style.display='none';
   document.getElementById('img_preloader_layer_div').style.display='none';
}
//************************************************************************
function ShowHide(id) 
{
	obj = document.getElementById(id);
   obj.style.display = (obj.style.display == "block" ? "none" : "block");
}
//************************************************************************
function Portfolio(id)
{
	var title='';
	//zamiana id na string z wypełnianiem 0
	if (id<10) filename='0'+id.toString()+'.jpg';
	else filename=id.toString()+'.jpg';
	//właściwe wyświetlanie
	ShowImageLayer('/img/portfolio/'+filename, title); 
}