How to update the contents of a text box when the selected row changes in a datagridview

I’m writing a simple application to track the time I spend working through out the week. I’ve made a form to edit the data so I don’t have to open the database everytime I need to change a value. One of the fields in the table is a Memo field to hold
notes about each job. It’s too large to display in the datagridview so I’ve bound a text box to the dataset. However, the text box does not change when I scroll up and down in the datagridview.

How can I get the text box to change with the data grid view as the rows are changing?

Use the SelectionChange Event of the datagridview  to update  the text  box with the memo  field.

Not sure what to use there? Do I use the dataset  or the datagridview?Jim