Input variables to control movie clip

Trying to build a piece where a truth table shows how a logic circuit’s output responds to various combinations of inputs, using logic 1 for true and logic 0 for false. User enters a four digit output string and is able to view the gate type that will produce it. (16 possible permutations in this e.g.)
Here is what I have so far. Any help greatfully appreciated.

Nom de Guerre
//initialize variables
var input_str:String = “”;

var Inner:String="";
Inner+text1.text;
Inner+text2.text;
Inner+text3.text;
Inner+text4.text;
//goto MC frame from input
function operate(){

_root.results.gotoAndStop._Inner;
}

// enter button
enter_btn.onRelease = function() {
//fill truth table out
input_strCharAt1=input_str.charAt(0);
input_strCharAt2=input_str.charAt(1);
input_strCharAt3=input_str.charAt(2);
input_strCharAt4=input_str.charAt(3);

}