<%@ Register Assembly="AsyncControls" Namespace="DelvingWare.AsyncControls" TagPrefix="dw" %>

<dw:AsyncButton runat="server" ID="btVisible"
CssClass="greyButton"
OnClick="btVisible_Click"
Text="Hide AsyncButton" />

<dw:AsyncButton runat="server" ID="btEnable"
CssClass="greyButton"
OnClick="btEnable_Click"
Text="Disable AsyncButton" />
<p />

<dw:AsyncButton runat="server" ID="btMain" 
OnClick="btMain_Click" 
Text="AsyncButton" />

using System;
using DelvingWare.AsyncControls;
...
protected void btMain_Click( object sender, AsyncEventArgs ae )
{
    // change the button text
    btMain.Text = "Clicked the AsyncButton";
}

protected void btVisible_Click( object sender, AsyncEventArgs ae )
{
    // change the visibility
    btMain.Visible = !btMain.Visible;

    // update the AsyncButton text
    if ( btMain.Visible )
        btVisible.Text = "Hide AsyncButton";
    else
        btVisible.Text = "Show AsyncButton";
}

protected void btEnable_Click( object sender, AsyncEventArgs ae )
{
    // upate the enabled state
    btMain.Enabled = !btMain.Enabled;

    // update the AsyncButton text
    if ( btMain.Enabled )
        btEnable.Text = "Disable AsyncButton";
    else
        btEnable.Text = "Enable AsyncButton";
}

Imports System
Imports DelvingWare.AsyncControls
...

Protected Sub btMain_Click(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    ' change the button text
    btMain.Text = "Clicked the AsyncButton"
End Sub

Protected Sub btVisible_Click(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    ' change the visibility
    btMain.Visible = Not btMain.Visible
    ' update the AsyncButton text
    If btMain.Visible Then
        btVisible.Text = "Hide AsyncButton"
    Else
        btVisible.Text = "Show AsyncButton"
    End If
End Sub

Protected Sub btEnable_Click(ByVal sender As Object, ByVal ae As AsyncEventArgs)
    ' upate the enabled state
    btMain.Enabled = Not btMain.Enabled
    ' update the AsyncButton text
    If btMain.Enabled Then
        btEnable.Text = "Disable AsyncButton"
    Else
        btEnable.Text = "Enable AsyncButton"
    End If
End Sub

.asyncButton {
    border: 0px;
    background-image: url("images/greyButton.gif");
    background-repeat: no-repeat;
    width: 120px;
    height: 25px;
}
.asyncButton:hover {
    background-image: url("images/greyButtonHov.gif");
    background-repeat: no-repeat;
    cursor: pointer;
}