Submit Button Conditional Logic - Unable to use

You have to include a select (drop down), radio or checkbox field to have something to trigger the conditional logic. The reason the option is grayed out is that you don't have any of those type of fields in your form.

http://www.gravityhelp.com/documentation/page/Enable_Conditional_Logic

What are you trying to do exactly. If you're trying to hide the button based on some condition, you need a field with basic options.. yes/no, etc. If you're just trying to hide the submit button for some odd reason, you could do that with CSS.

[css]
body #gform_wrapper_1 .gform_footer input[type=submit] {display:none}

Try saving your form, then go to Edit Forms and edit your form again and then edit the field and go to the conditional logic again and let me know if it's grayed out still.

Please note conditional logic requires a selection field to exist on your form (ex. drop down, radio button or checkbox field).

Okay, I understand now. You would need to just hide the button with CSS. Use the example I posted above, but replace the "_1" with your actual form ID.