Paypal button per member

[t3nt3tion]

<if condition="$post['field5']">

<input type="hidden" name="cmd" value="_xclick">
<input type="hidden" name="business" value="$bbuserinfo[field5]">
<input type="hidden" name="page_style" value="PayPal">
<input type="hidden" name="no_shipping" value="2">
<input type="hidden" name="no_note" value="1">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="tax" value="0">
<input type="hidden" name="bn" value="PP-DonationsBF">
<input type="image" src="https://www.paypal.com/en_US/i/btn/x-click-but21.gif" border="0" name="submit" alt="Make payments with PayPal - it's fast, free and secure!">
<img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
</form>

</if>

I added that in the postbit template, so I can show a paypal donate button. My problem is that when I click the button it`s taking me to a page : inlinemod.php

If I look in the source code, I can see the field being change with my option, but it`s not redirecting me to the right page.