Can we write in UPPERCASE while caps Lock is off?

1

HI friends,
I am making a quiz.
user will give answer in input text field, so i wrote like this,

submitBtn.addEventListener (MouseEvent.CLICK, q3);

function q3 (evt:MouseEvent):void {
    var ans3T:String;
    ans3T = inputTxt.text;

    if (ans3T == "gyan")
    {
        trace ("correct answer");
    } else
    {
        trace ("wrong answer");
    }
}

but problem is if user type Gyan or GYAN, it will say wrong so
how can i fix this problem,
can we write in UPPERCASE while caps Lock is off,
or
can we restrict UPPERCASE in input text Field ??