DatagridView

Question

I have one comboBox which connected with database and one datagridview.

As, I click on combox the list items are populating, and after selecting one of them person name, all the regarding data comes in DataGridView (i.e.family Members Name, Age, Education etc.)

Suppose, 

Mr.ABC already save some information in Table "Myself" (i.e. His father's, Mother's and His own information)

Now, In modify form, after selecting his name from comboBox, all the data automatically comes in DatagridView.

Now, he want to add his brother's and Sister's information in DataGridView & save/Update it.

(But all this process must be done directly from datagridView)

1. We give a link to add another row in DataGridView.

After click on link one extra row will add in DatagridView.

2. After adding row, User starting to type new data in new row added.

3. At last, on button click, new data will be save/updated in "Myself" table on his particular data only...

How it can be done?