var xmlHttp;
var url;

function show ( file, parent, type, php ) {
   xmlHttp = GetXmlHttpObject ( );
   if ( xmlHttp == null ) {
      alert ( "Browser does not support HTTP request" );
      return
   }
   if ( php == 1 ) {
      url = file;
   }
   else {
      url = type + ".php";
      url = url + "?f=" + file + "/";
      url = url + "&p=" + parent;
   }
   xmlHttp.onreadystatechange = stateChanged; 
   xmlHttp.open ( "GET",url,true );
   xmlHttp.send ( null );
}
   
function stateChanged ( ) { 
   if ( xmlHttp.readyState==4 || xmlHttp.readyState=="complete" ) { 
      document.getElementById ( 'main' ).innerHTML=xmlHttp.responseText;
   } 
}
   
function GetXmlHttpObject ( ) {
   var xmlHttp = null;
   try {
      // Firefox, Opera 8.0+, Safari
      xmlHttp = new XMLHttpRequest ( );
   }
   catch ( e ) {
      //Internet Explorer
      try {
         xmlHttp = new ActiveXObject ( "Msxml2.XMLHTTP" );
      }
      catch ( e ) {
         xmlHttp = new ActiveXObject ( "Microsoft.XMLHTTP" );
      }
   }
   return xmlHttp;
}