Close the child window before submit the form

Close the child window before submit the form

I have a table data in a form and there is dynamic link in each row which
opens an external link in a new window. These rows are in n numbers with
dynamic id.
What I need here is,when user try to submit the table details, they must
close all the child windows. If any child div is still opened and if he
tries to submit the form, it should given alert to close the child windows
Here is the sample DEMO of the form
<form>
<table border="1">
<tr>
<td><input type="text" /></td>
<td>SC1</td>
<td><a href="http://www.google.com">this is an external
link</a></td>
<tr>
<td><input type="text" /></td>
<td>SC2</td>
<td><a href="http://www.google.com">this is an external
link</a></td>
<tr>
<td><input type="text" /></td>
<td>SC3</td>
<td><a href="http://www.google.com">this is an external
link</a></td>
</tr>
</table>
<input type="submit" value="submit" />
</form>