I am trying to use simplePopUp to display a form I made. When inserting {loadposition form} it does work and the form displays on my page, as soon as I add the popup around it (as shown in the documentation) it opens as a blank popup with no content in it. I also tried using the pre-existing login form but the same problem occurs. What could I be doing wrong?
See my code:

{simplepopup popup="false" name="formlogin"}
{loadposition form}
{/simplepopup}
{simplepopup link="formlogin} Click here to open the form! {/simplepopup}