首先，写入一个div，这个div就是以后提示用户等待的框
<div class="divcenter" id="popupLoad" align="center" name="loadpop" style="DISPLAY:none">
                                <TABLE class="popload" style="FONT-SIZE: 11px; FILTER: Alpha(opacity=75); LINE-HEIGHT: 18px; TEXT-ALIGN: left"
                                    cellSpacing="1" cellPadding="5" bgColor="#c5c7c1" summary="Loader Layout" border="0">
                                    <TBODY>
                                        <TR>
                                            <TD vAlign="middle" align="left" bgColor="#ffffff">
                                                <P><IMG style="MARGIN: 3px" height="32" alt="请等待" src="../images/clock.gif" width="32" align="left"><STRONG>估价报告生成中</STRONG><BR>
                                                    <SPAN style="FONT-SIZE: 9pt">根据网络速度的不同，报告生成需要占用您几分钟事件，请耐心等待</SPAN></P>
                                            </TD>
                                        </TR>
                                    </TBODY>
                                </TABLE>
                            </div>
然后在form_load里面，给button注册属性
Button1.Attributes.Add("onClick", "document.all.popupLoad.style.display='';")

这样在执行比较大的事件的时候，就可以以一个假相迷惑用户，用户不至于事件长而烦躁。