function sprawdzPlugina(plugin, theURL, altURL, IEGoesToURL) { 
if ((navigator.plugins && navigator.plugins[plugin]) || (IEGoesToURL && navigator.appName.indexOf('Microsoft') != -1 && navigator.appVersion.indexOf('Mac') == -1 &&  navigator.appVersion.indexOf('3.1') == -1)) { 
    if (theURL.length>2) adres_www = theURL; 

    } else { 
        if (altURL.length>2) adres_www = altURL; 

    } 
	
	window.open(adres_www,'topologia','toolbar=no,location=no,status=no,menubar=no,scrolbars=no,resizable=no,width=680,height=467,top=20, left=20');

    document.MM_returnValue = false; 

}