Hi,
With your help, the HTML code I needed is:
<p align="center"><input name="q_doanswer" onclick="return qa_toggle_element('anew')" value="Post an answer" title="Answer this question" type="submit" class="qa-form-tall-hover qa-form-tall-hover-answer"></p>
I pasted this HTML code in qa-theme.php of theme folder inside the function you provided above. However, am getting this error
Parse error: syntax error, unexpected T_STRING in /home/xyz/public_html/qa-theme/Snow/qa-theme.php on line 94
And Line 94 is: <p align="center"><input name="q_doanswer" onclick="return qa_toggle_element('anew')" value="Post an answer" title="Answer this question" type="submit" class="qa-form-tall-hover qa-form-tall-hover-answer"></p>