How to allow input text field to accept more than one "specific" answer.

Question

Hi,
I am working for something and trying to create a type-box-based quiz for one of my classes, where an input text field can change it's border color if 2 or more words from an accepted word list is inputed.
For example, Say a list has possible answers: R,G, B, Y for the question "Name 2 colors".
I want to create an input text box where the border of the box will change color if any 2 letters (in the above list) are entered into it.
I've tried setting up a variable NumberSuccesses and setting it so that the number increases by 1 for each letter entered e.g.
if (Ex.text == "R");
NumSuc = NumSuc +1; // the var NumSuc has already been defined earlier in the code
If (Ex.text ''G")
NumSuc = NumSuc + 1
if (NumSuc == 2)
Ex.borderColor = 0x0000FF
but that didn't work.. and I tried doing it with another function which I use for multiple input boxes like if there were boxes A, B, C. I could set up a general function where if the correct answers were entered into A, B, an C respectively, only then will say, a checkmark show up using a
EnableCheckmark (); type function. Not sure how to do it if it's the same text input box though. Also just tried adding it into the same function re.
If (Ex.text == "R" + "G")
Ex.borderColor = 0x0000FF
.. Does anyone know what else I can do?

Answer 1

The solution of Nishu with Evaluation Logic:
//These Are the Possible Answers
var solutions:Array = new Array("A","B","C","D");
function testInput(_inputText:String):Boolean
    //the delimiter could also be a comma, here it is a space
    var inputStringArray:Array = _inputText.split(" ");
    var counter:Number = 0;
    for (var i:int=0; i<inputStringArray.length; i++)
        for (var j:int=0; j<solutions.length; j++)
            if (inputStringArray[i]== solutions[j])
                counter++;
    if (counter >=2)
        trace("true");
        return true;
    else
        trace("false");
        return false;
//Textfield with name input_txt on stage
input_txt.addEventListener(TextEvent.TEXT_INPUT, answerTxtInp);
// The function that will be called by the event listener
function answerTxtInp(txtEvent:TextEvent):void
     // depending on the possible answers of characters, change the border  color
     if(testInput(input_txt.text)){
         input_txt.borderColor = 0xFF0000;
     else{
         input_txt.borderColor = 0x000000;