This way
HTML
<asp:Button ID="Button1" Text="Submit1" runat="server" OnClick="Submit" />
<asp:Button ID="Button2" Text="Submit2" runat="server" OnClick="Submit" />
<asp:Button ID="Button3" Text="Submit3" runat="server" OnClick="Submit" />
C#
protected void Submit(object sender, EventArgs e)
{
string id = (sender as Button).ID;
string text = (sender as Button).Text;
}
VB.Net
Protected Sub Submit(ByVal sender As Object, ByVal e As EventArgs)
Dim id As String =(TryCast(sender, Button)).ID
Dim text As String =(TryCast(sender, Button)).Text
End Sub