Need a script to Hide an Html element based on the the number in another html element

Need a script to Hide an Html element based on the the number in another html element

Hello

I am working on a e-commerce site and I need to hide the checkout link (<a>) if the value of of the element (<td>) holding the amount due ="$0.00". 

 
<tr>
<td colspan="4" class="impact subtotal">Outstanding:</td>

this amount is generated from the shopping cart database
<td>$0.00</td>


</tr>
</table>
</td>
</tr>
</table>












this is the link that needs to be hidden if the amount of the above element
is $0.00

<a class="impact purchase_btn" href="#">PURCHASE ORDER</a>


I am new to Jquery so if someone could point me in the right direction 
that would be helpful. Thanks