// Puts a Text Input to its other state or back.
function swapTextInputs(ID) {

    // The two text inputs to be swapped always have
    // their ids like "TextInput_" and "TextInput".

    if(ID.charAt(ID.length-1) == '_') {
        document.getElementById(ID).style.display = "none";
        document.getElementById(ID.substr(0,ID.length-1)).style.display = "block";
        document.getElementById(ID.substr(0,ID.length-1)).focus();
    }
    else {
        // Swapping the text input only if it is empty.
        if(document.getElementById(ID).value.length == 0) {
            document.getElementById(ID).style.display = "none";
            document.getElementById(ID+"_").style.display = "block";
        }
    }
}

// Sets the height of a Textarea based on the height of its content.
function manageTextareaHeight(ID) {
    var textarea = document.getElementById(ID);
    textarea.style.height = "10px";
    textarea.style.height = (textarea.scrollHeight+10)+"px";
}