function viewPic(img)
{ picfile=new Image(); picfile.src=(img); fileCheck(img); }

function fileCheck(img)
{ if((picfile.width!=0)&&(picfile.height!=0))
	{ makeWindow(img); }
	else { funzione="fileCheck('"+img+"')"; intervallo=setTimeout(funzione,50); }
}

function makeWindow(img)
{ ht=picfile.height+20; wd=picfile.width+20;
  var args="height="+ht+",innerHeight="+ht;
	args+=",width="+wd+",innerWidth="+wd;
	if (window.screen)
	{ var avht=screen.availHeight; var avwd=screen.availWidth;
		var xcen=(avwd-wd)/2; var ycen=(avht-ht)/2;
		args+=",left="+xcen+",screenX="+xcen;
		args+=",top="+ycen+",screenY="+ycen+",resizable=1,scrollbars=0"; 
	}
  return window.open(img, '', args); 
}