How to send input text to web browser (e.g. Translate, Ivona, Watson) for Text to Speech?

Hi there :)

I'm creating an input/output UI that allows the user to press 'play' and hear the passage they've just entered. The code for this (similar to a chat box like MSN) is as follows

 using UnityEngine;
 using System.Collections;
 using UnityEngine.UI; 
 using System.Text.RegularExpressions; 
 using UnityEngine.Audio; 
 using System.Net; 
 
 public class KeyboardInput : MonoBehaviour {
     public AudioSource audio; 
     InputField input; 
     InputField.SubmitEvent se;
     public Text output; 
     public string url = "https://www.ivona.com/";
 
     // Use this for initialization
     void Start () {
         input = gameObject.GetComponent<InputField> (); //this will be attached to inputfield. 
         se = new InputField.SubmitEvent(); // puts what is in the inputfield into the submitinput method
         se.AddListener(SubmitInput);//When there's an event it looks for the method to call when this event triggers "Go to this method which is" 
         input.onEndEdit = se;
 
         Application.OpenURL(url); 
         WWWForm Ivona = new WWWForm(); //This web site opens in the browser in game mode. this is where we want what we type to also appear
     
 
     }
 
 
     private void SubmitInput(string arg0) //the string is by default called arg0. void as it does a thing, then returns
     {
         string currentText = output.text; //.ToString (); 
         string newText = currentText + "\n" + arg0; //concat of current and new text, "\n" is newline/linebreak, adding in the string from above
 
         output.text = newText; //this sets the string as the output
         input.text = ""; //clears the text from the window when u hit enter
         input.ActivateInputField(); //activates our input so we can type stuff in
 
     }
 }

My problem is that I don't know how to take what I input and send it to the web site I'm using to enable text-to-speech. I thought that putting the SendMessage command would do it, but nope :/ Any pointers would be appreciated - even just something to get me heading in the correct direction would be lovely!

Best Wishes!