Are you having trouble hitting the submit button when it is Greyed out? See article below for details
The issue is that one of the fields/boxes that is required to be filled has not been filled. If the field is not filled then the submit button will not be lit up. Fields/boxes that are required will have a green border around them.
Fields/boxes that are required will have a green border around them. Fields/Boxes that are not required will have a yellow box around them. See the screenshots above as a guide.