I am new to the software but I am enjoying playing around with it, I was wondering if there was a reason as to why I cannot delete one of the fields on this form. 

The error message is as follows;

"This field is referred as display fields in the following places. Please remove them and then delete this field."

"Advanced Display Fields"

"1.Customer Contact List - Asset Manager - Sales Order No."

I can't seem to find the relationship, if that is indeed the problem. Thanks in advance for any help you may be able to give.