aspnet中button的属性 ASP.NET ImageButton OnClientClick 属性

<script runat="server">
Sub script1(obj As Object, e As ImageClickEventArgs)
  lblMsg.Text="Hello!"
End Sub
</script>

<form runat="server">
<asp:ImageButton OnClick="script1" OnClientClick="script2()"
ImageUrl="img.gif" runat="server" />
<br />
<asp:label id="lblMsg" runat="server" />
</form>

<script>
function script2()
  {
  return confirm("Hello!");
  }
</script>