PlayerPrefs not working with android

in my simple Game when i try to set the high score it works in unity editor and windows build but not in android build

 #pragma strict
  
  public var scoreTxt :GameObject ; 
  public var bestScoreTxt :GameObject ; 
  var currentBestScore  ;

function Start () {
 	 
	bestScoreTxt.GetComponent.<UI.Text>().text =	PlayerPrefs.GetString("Best",scoreTxt.GetComponent.<UI.Text>().text) ; 


	var target : motoScript = GetComponent (motoScript) ;

	bestScoreTxt.GetComponent.<UI.Text>().text =	PlayerPrefs.GetString("Best");

	if(float.Parse(scoreTxt.GetComponent.<UI.Text>().text) >=float.Parse(bestScoreTxt.GetComponent.<UI.Text>().text)){
	bestScoreTxt.GetComponent.<UI.Text>().text = scoreTxt.GetComponent.<UI.Text>().text ; 
		PlayerPrefs.SetString("Best" ,bestScoreTxt.GetComponent.<UI.Text>().text  ) ; 


	}


}

It Worked now when i changed “SetString” to “SetInt” here is the new code

 #pragma strict
  
  public var scoreTxt :GameObject ; 
  public var bestScoreTxt :GameObject ; 
  var currentBestScore  ;

function Start () {

 	 	 
	bestScoreTxt.GetComponent.<UI.Text>().text =	PlayerPrefs.GetInt("Best",0).ToString() ; 


	var target : motoScript = GetComponent (motoScript) ;

	bestScoreTxt.GetComponent.<UI.Text>().text =	PlayerPrefs.GetInt("Best").ToString();

	if(float.Parse(scoreTxt.GetComponent.<UI.Text>().text) >=float.Parse(bestScoreTxt.GetComponent.<UI.Text>().text)){
	bestScoreTxt.GetComponent.<UI.Text>().text = scoreTxt.GetComponent.<UI.Text>().text ; 
	PlayerPrefs.SetInt("Best" , float.Parse(bestScoreTxt.GetComponent.<UI.Text>().text ) ) ; 


	}


}