DroidScript isPlugin function

// DroidScript
// Check if a file has the structure of a plugin

var fil = "/storage/9016-4EF8/Download20160702/FileManager.zip";
//fil="/storage/9016-4EF8/Download20160702/3Dumb.zip";
function OnStart()
{
     var msg ="Invalid Plugin";
     if(isPlugin( fil )) msg = "Looks OK"
     app.ShowPopup( msg );
}

function isPlugin(fil)
{
    return isPluginZip(fil) || isPluginApk(fil);
}

function isPluginApk(fil)
{
   var temp = fil.split("/").pop();
   if(temp.slice(-4)!=".apk") return false;
   var plugName = temp.slice(0,-4);
   var zip = app.CreateZipUtil(  );
   zip.Open( fil );
   var lst = zip.List( "/" ).split(",");
   if(lst.indexOf("classes.dex")==-1) return false;
   lst = zip.List( "/assets/" ).split(",");
   if(lst.indexOf(plugName+".inc")==-1) return false;
    if(lst.indexOf(plugName+".html")==-1) return false;
   return true;
}

function isPluginZip(fil)
{
   var temp = fil.split("/").pop();
   if(temp.slice(-4)!=".zip") return false;
   var plugName = temp.slice(0,-4);
   var zip = app.CreateZipUtil(  );
   zip.Open( fil );
   var lst = zip.List( "/" ).split(",");
   if(lst.indexOf(plugName+".jar")==-1) return false;
   if(lst.indexOf(plugName+".inc")==-1) return false;
    if(lst.indexOf(plugName+".html")==-1) return false;
   return true;
}