function popUp(link,breite,hoehe) 
	{
	hoehe = hoehe - 20; 
	
	var x = 0, y = 0;
	
	if (breite < screen.availWidth || h < screen.availHeight) 
		{
		x = (screen.availWidth  - breite)  / 2;
		y = (screen.availHeight - hoehe  - 104) / 2;
		
		if (window.opera) 
			{
			y = 0;
			}
		
		if (x < 0 || y < 0) 
			{
			x = 0; y = 0; 
			}
		}
		
  popup = window.open(link,'Grafikverwaltung','width=' + breite + ',height=' + hoehe + ',left=' + x + ',top=' + y + ',menubar=no,location=no,toolbar=no,status=no,resizable=no,scrollbars=yes');
  
	popup.focus();
	}