//Note line commented below is replaced by the following
//if (submitKey0 != KeyCode.None && Input.GetKeyDown(submitKey0))
if (cInput.GetKeyDown("YourSubmitButtonName")) {
currentKey = submitKey0;
submitKeyDown = true;
}
//Note line commented below is replaced by the following
//if (submitKey0 != KeyCode.None && Input.GetKeyUp(submitKey0))
if (cInput.GetKeyUp("YourSubmitButtonName")) {
currentKey = submitKey0;
submitKeyUp = true;
}