Making & displaying a list of highscores

So I know this question has been asked numerous times and I found a few places but I still cannot properly wrap my head about this. I'm using this as a base but it hasn't been updated in years so I'd figure it would be better to ask a new question: http://answers.unity3d.com/questions/20773/how-do-i-make-a-highscores-board.html

I just need help figuring out some of the logic of what the next steps should be. Basically in my game you keep playing till you die. Game will then display your current score and the highscore button will show you a list of scores like so:

1. 90

2. 50

3. 45

4. 20

5. 11

The highscore can be accessed from 2 gamescenes (the main menu and the actual game scene) so playerprefs would be used in this case. So far I came up with this:

 var topScores: float[];  //array to store our scores
 var scoreTxts: Text[]; //array to store our text
 var newScore: float; //the score we just made
 var oldScore: float; //the previous score to check against
 
 
 function CheckScore(){ 
     for(var i = 0; i < topScores[i]; i++){ //go through the array to check the following
         if(PlayerPrefs.GetFloat(i+"HScore")<newScore){ //checks if the score in the array is higher than your new score
             // new score is higher than the stored score
             oldScore = PlayerPrefs.GetFloat(i+"HScore"); //gets the old score that our new score is higher than
             PlayerPrefs.SetFloat(i+"HScore",newScore); //sets the new score to overwrite the old score
             newScore = oldScore; //overwrites the float to be checked again
             
         }
         else{
             PlayerPrefs.SetFloat(i+"HScore",newScore); //keeps the newscore as is
              newScore = 0; //resets the newscore to be checked again
       }
     }
     DisplayScore(); 
 }
 

I don't know if I'm on the right track or even how to test this but the idea is that I would have an array of floats and an array of texts. I think I got the first part right (storing the score, not sure how to test that) and now I'm trying to wrap my head around using the 4.6 gui system to check that array and display the scores.

Also one last thing, for debugging is it wise to use playerprefs.clearall? Or is there a "safer" way to wipe out your highscore?