Monthly donations as subscription in PayPal

I understand that if I want to set up monthly donations in PP I should use the Subscriptions button. But I'm wondering how you can do that and leave the amount variable?

Thank you.

You will need to add in your subscription button then update the html on the page to make the price field an editable text field.

So if you have the price field rite now in the form as a hidden field you can just update it to be a type="text" input instead. This way the user can enter their own amount.

Thank you for your reply.

Just to be sure I understand, so then instead of
<input type="hidden" name="a3" value="1.00" />

I would put
<input type="text" name="a3" value="" />

leaving the a3 value blank?

Thank you.

I don't have a sample PayPal subscription button to compare to but if this is the value that you set for the subscription amount then you are correct. Even if this is not the correct element the update that you made is correct, you just need to turn the value from a hidden form element to a text element.