How check javascript not to open the same window with window.open function
<p>In my javascript i want to open URL in new window with this method:</p>

<pre><code>var win = window.open(url...);
</code></pre>

<p>How can i check this, not to open the same window and lose all inputted data.
For example, if i opened "www.musite.com/addproduct" URL in new window, input data, leave my work place. then i click open window again, new window open and i lost all my data.</p>
