Button for Best Answer or: Adding a value to $this->post_hover_button

Question

Instead of a graphic I want to add a button "best answer?", for that the input field needs a value (which will be the label of the button):

<DIV CLASS="qa-a-selection">
    <INPUT TITLE="Click to select as best answer" NAME="a20685_doselect" onclick="return qa_answer_click(20685, 20684, this);" TYPE="submit" VALUE="" CLASS="qa-a-select-button" onmouseover="this.className='qa-a-select-hover';" onmouseout="this.className='qa-a-select-button';">
</DIV>

Can I just set "best answer?" as a value?

I see that the onclick throws even the value to the server, which is used as:

document.forms['q_page_form'].elements['qa_click'].value=target.name;

see qa-question.js

So what is this line doing? And what will happen if target.name == "best answer"?

Thanks!