捕获搜索文本，并在单击“提交”时将其传递到URL中

I just cant get around this simple requirement. I am new to PHP and need help.

I need to capture the value in a Search Box and then pass it in the URL which opens in a new tab when hit on Submit.

What am I missing here..it seems like I am missing a lot of things for this to work..

<?php
 if (isset($_POST["submit"])){
    $example = $_post['searchon'];
    echo '<a target = '_blank' href=http://www.amazon.in/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=.$example.&tag=orientmarketi-21></a>';
 }
?>  

  <form action="index.php" method="post">
    <input type="search" name="searchon" id="searchon" />
    <input type="submit" name ="submit" />
        </form>

try this code instead of your one:

<form action="http://www.amazon.in/s/ref=nb_sb_noss_1" method="get" target="_blank">
<input type="hidden" name="url" value="search-alias=aps" />
<input type="hidden" name="tag" value="orientmarketi-21" />
<input type="text" name="field-keywords"/>
<input type="submit" />
</form>