browserName = navigator.appName;           
browserVer = parseInt(navigator.appVersion);  
var alt = "Ready";

    if ((browserName == "Netscape" && browserVer >= 3) 
     || (browserName == "Microsoft Internet Explorer" && browserVer >= 4)) version = true;
        else version = false;
             
    
	function Replace(Name, Source) 
	{
	   if (version == true) 
	   {    
		  document[Name].src = Source ;				
	   }

	   return true;

	}