here is what I understand....
you have got 2 Submit button in a form.
> When clicked on 1st it should load the active page in the same window and
> when clicked on 2nd it should load active page in new window.
You are trying achieve above behavior using below PHP Code...
<?php if (isset($_POST['empList'])):??>
<?php if (isset($_POST['Report'])):??>
I think there is a bug in your code. When page is initially loaded base tag will not be set, because both if conditions will be false.
You have to write client side code to achieve your said behavior. Following is sample code...
<input type="Submit" value="Self" onclick="document.forms.target='_self';">
<input type="Submit" value="New Window" onclick="document.forms.target='_blank';">