problem of save screenshot in iphone using prime31 plugins

Hello everyone,

I want to save screenshot of game in iphone gallery . but when i click on save button it saved previous screenshot . please help me it is urgent for me.

string GetDocumentsPath() {

string DocumentsPath;

     DocumentsPath = Application.dataPath.Substring (0, Application.dataPath.Length - 5); 
        DocumentsPath = DocumentsPath.Substring(0,DocumentsPath.LastIndexOf("/"));
        return DocumentsPath + "/Documents/";
 
 }

public void SaveWallpaperPrompt() {

     StartCoroutine( EtceteraBinding.takeScreenShot("te.png") );
     
     saveImage(2f);
     if(File.Exists (GetDocumentsPath()+"te.png"))
     {
         Debug.Log ("------------------- File Exits");
         EtceteraBinding.saveImageToPhotoAlbum(GetDocumentsPath()+"te.png");
     }
         else
     {
         Debug.Log("------------ File NOT FOUND");
     }
     
 
 }


  IEnumerator saveImage(float tm)
 {
     
     
     yield return new  WaitForSeconds(tm);
     
 
     
 }