Partial Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        'bind the alertbox() and confirmbox function to button control
        Button1.Attributes.Add("onclick", "alertbox();confirmbox();")
    End Sub
End Class

    < script type ="text/javascript" >
    function alertbox()
    {
    alert("This is first function");
    }
    function confirmbox()
    {
    confirm ("This is second function") ;
    }
    < /script>