I have some elements in my document like:
<div class="checkbox-inline"><label><input id="mylabel" value="False" type="checkbox">mytext</label></div>
I'm assuming you're trying to access the text of the label element, in this case "mytext"? The reason this isn't working is because the id is on the input element, whcih doesn't actually contain that text
<input id="mylabel" value="False" type="checkbox">
That's the entirety of your input element.
As others have stated, you can get the value of that element using
Which will give you "False"
However, if you do need the text "mytext" and don't want to change your markup you can use this
Which gets the element with the mylabel id, finds it's parent element (in this case the label element) and then gets the text from that element.
Now that you know that, you might realise that it's easier to just put an id on the label!