[File-explorer]How Implements a crude file browser in Unity3d?

Friends , it is very good help in our progress ! Now I need your help . I am wanting to create a File - Explorer to access my sdcard directory on Android .

Because the programmer created this solution with a code that does NOT belong to MonoBehaviour class ? HOW COULD BE IMPLEMENTED ?

Code Complete ( http://wiki.unity3d.com/index.php?title=FileBrowser )

public static bool FileBrowser( ref string location, ref Vector2 directoryScroll, ref Vector2 fileScroll )

{

 bool complete;

 DirectoryInfo directoryInfo;

 DirectoryInfo directorySelection;

 FileInfo fileSelection;

 int contentWidth;
 
 
 // Our return state - altered by the "Select" button
 complete = false;
 
 // Get the directory info of the current location
 fileSelection = new FileInfo( location );
 if( (fileSelection.Attributes & FileAttributes.Directory) == FileAttributes.Directory )
 {
     directoryInfo = new DirectoryInfo( location );
 }
 else
 {
     directoryInfo = fileSelection.Directory;
 }
 
 
 if( location != "/" && GUI.Button( new Rect( 10, 20, 410, 20 ), "Up one level" ) )
 {
     directoryInfo = directoryInfo.Parent;
     location = directoryInfo.FullName;
 }
 

            ................................

Here 's how to use it , but FileBrowserWindow is not in the current context :

Code Complete ( http://wiki.unity3d.com/index.php?title=FileBrowser )

    public void FileBrowserWindow( int idx )

 {

     if( FileBrowser( ref location, ref directoryScroll, ref fileScroll ) )

     {

         fileBrowser = false;

     }

 }
 
 public void OnGUI()

 {
     if( fileBrowser )

     {
         GUI.Window( 0, new Rect( ( Screen.width - 430 ) / 2, ( Screen.height - 380 ) / 2, 430, 380 ), FileBrowserWindow, "Browse" );
         return;
     }
 }

THERE'S SOMETHING MISSING DO .

PLEASE HELP ME TO DO THIS CODE WORK .

Come together to advance !