Prevent dynamic form submits if same data already exists

Show user a (data already exists) popup message when submit the form if the user enter same data that already exists on the server by identifying two fields 1- StudentName, ChildName & FatherName, Parent Name

NOTE:
Form: https://idsupply.in/app/online/data/676/630e6e0fdf720f5422ec55b0ee91f559ac865502
Duplicate data received: https://prnt.sc/MleVeLujyDFO
Dynamic form file attached, java scripts are written below of the file