suppose ,there r 3 buttons & we have to handle all button 
click events at once. Then try following steps
1) Write eventhandler 

 Public Sub clickevent(ByVal sender As Object, ByVal e As   
System.EventArgs) Handles Button1.Click, Button2.Click, 
Button3.Click
        Dim b As Button = CType(sender, Button)
        Response.Write("hello:" & b.Text)
 End Sub
2) then call this event handler on click event of eech 
buttons.