How do I create runtime inputs?

Hi everyone, I'm making a maths game in unity which in essence displays an equation using the GUI and then the player must type in a number to progress.

I am using javascript but not too sure how I can have the player enter a number and have the game compare it to the right answer. I tried using GUI.TextField and I am able to enter a number, but I am not able to get the game to compare the answer.

This is my code so far, any help will be greatly appreciated!

Thanks in advance!

 //system variables
 
 public var guiSkin : GUISkin;
 
 var solved : boolean = false;
 var correct : boolean = false;
 var wrong : boolean = false;
 var gameOver : boolean = false;
 
 var smallRandom1 : int;
 var smallRandom2 : int;
 var answer : int;
 var inputAnswer = " ";
 
 var randomOperator : int;
 var displayOperator = " ";
 
 function Start () 
 {
     // randomizing numbers and operator
     smallRandom1 = Random.Range(0, 21);
     smallRandom2 = Random.Range(0, 21);
     randomOperator = Random.Range(0,4);
 }
 
 function Update () 
 {
     // displaying opposite operator
     OnScreenOperator();
     
     // perform calculation when enter is pressed
     if(Input.GetKeyDown(KeyCode.Return))
     {
         print("pressed Enter");
         Calculate();
     }
 }
 
 // function for displaying opposite operators. eg + is displayed as -
 function OnScreenOperator()
 {
     if(randomOperator == 0)
     {
         displayOperator = "-";
     }
     if (randomOperator == 1)
     {
         displayOperator = "+";
     }
     if (randomOperator == 2)
     {
         displayOperator = "/";
     }
     if (randomOperator == 3)
     {
         displayOperator = "x";
     }
 }
 
 // numbers calculation
 function Calculate()
 {
     if(randomOperator == 0) // addition
     {
         answer = smallRandom1 + smallRandom2;
         print(answer);
     }
     if (randomOperator == 1) // subtraction
     {
         answer = smallRandom1 - smallRandom2;
         print(answer);
     }
     if (randomOperator == 2) // multiplication
     {
         answer = smallRandom1 * smallRandom2;
         print(answer);
     }
     if (randomOperator == 3) // division
     {
         answer = smallRandom1 / smallRandom2;
         print(answer);
     }
 }
 
 function OnGUI()
 {
     // storing chalk font
     GUI.skin = guiSkin;
     
     // drawing chalk font on screen
     GUI.Label(Rect(Screen.width/4,Screen.height/2.5,1000,1000),
     smallRandom1.ToString() + " " + displayOperator + " " + smallRandom2.ToString() + " = ?");
 }