Easy problem but can't find answer

[kau]

I have a form.
The form submits data to a PHP document.
The PHP document gets the data like this:

$Article = $_POST["Article"];
$Topic = $_POST["Topic"];
$Subject = $_POST["Subject"];
.......

Then I submit into the database like this:

$sql = "INSERT INTO faq (topic, article, header, name, email, id, display, screen_name, date, IP)
VALUES
('$Topic', '$Article', '$Subject', '$Name', '$Email', $random,'No', '$ScreenName', '$date', '$domain')";
mysql_query(sprintf($sql));


All works well.

Unless I submit this link:
<a href="http://www.jeep.com/wccsapp/universal/J/index.jsp?appStr=wccs&titleStr=Contact+Jeep&family Str=brand&franchise=J&actionURL=%2Fwccs%2Fbrand_fo rms%2Fus%2Fwebform.jsp&promotion=null&category=U)h ttp://www.jeep.com/wccsapp/universal/J/index.jsp?appStr=wccs&titleStr=Contact+Jeep&family Str=brand&franchise=J&actionURL=%2Fwccs%2Fbrand_fo rms%2Fus%2Fwebform.jsp&promotion=null&category=U">http://www.jeep.com/wccsapp/universa...ull&category=U)http://www.jeep.com/wccsapp/universal/J/index.jsp?appStr=wccs&titleStr=Contact+Jeep&family Str=brand&franchise=J&actionURL=%2Fwccs%2Fbrand_fo rms%2Fus%2Fwebform.jsp&promotion=null&category=U</a>

Then the $Article variable shows up null and the INSERT statement won't work.

Why?