REGEX-Escape for: <a href="http://sildenafil03.us.org/">sildenafil</a>

Your Input:
Result, the escaped string:

What must the escaping look like for:
<a href="http://sildenafil03.us.org/">sildenafil</a>

The excaped text for use in a regex is:
\<a href\="http\:\/\/sildenafil03\.us\.org\/"\>sildenafil\<\/a\>