Custom JOptionpane

Steps to follow 1. Create 2 textfields ( Name, Mark) 2. If the cursor is pointing to Mark Custom JOptionpane to input A, B, C, D, E If the user clicks No, Mark field should be updated with 0 If th user clicks Yes, if Sum (A,B,C,D,E) = 1, mark should be updated with 1, otherwise the JOptionpane show show a error message until sum is 1 or till the user clicks No. 3. If the cursor comes to Name and then moves to mark, Step 2 Budget - 5 USD Thanks Alwyn