Visual Basic MySQL Datagrid Delete From Database?

I am making a invoice system in Visual Basic 2010 and i am stuck here Here is my code

Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click
For Each row As DataGridViewRow In datagrid.SelectedRows
Dim selectedindex As String = datagrid.CurrentRow.Cells(0).Value.ToString()
datagrid.Rows.Remove(row)

[Code]...

This code is not working well please have a look to my invoice screen shot and suggest me a better code

When i try to delete the selected row the code does not work and if any one can tell me i can delete multiple selected rows? they are deleted from the datagrid but not from database