this.name possibly an issue?

Hi, I'm having a hard time understanding where certain variables are stored./ accessed

I have created a public variable at the top of my main script

Code (csharp):

1.  
2. public var cardmatches=new Array();
3.  

I can edit and change this within the update function and works fine

my problem is if I try and make changes within the mousedown() function where i have the following code

Code (csharp):

1.  
2. if (this.tag=="card1")
3.    {
4.        cardmatches[1]=1;
5.  
6.    }
7.  
8.  

If I run the following from within the update() function it returns nothing, doesnt show cardmatches with the value of 1.

Code (csharp):

1.  
2. Debug.Log("cardmatches within this tag = "+cardmatches[1]);
3.  

I presume its something to do with it storing it within an instance and thats why the variable isnt updating but dont quite understand how i can proceed..

Any help with this would be appreciated, thanks