DDSlick hiding behind when opened in a modal form

DDSlick hiding behind when opened in a modal form

I am trying to open ddslick with images in a modal form. It opens fine, but the issue is when you click on the down arrow to expand the dropdownlist, the list hides within the modal form. User has to scroll the form to select a image. I want the dropdown list to expand on top of the modal form just like a normal dropdown list would in a modal form. Please advise!