将以下代码保存为htm或html文件在浏览器里一看便知效果.
<SCRIPT language=javascript>
function switchbar(){
if (switchPoint.innerText==3){
switchPoint.innerText=4
document.all("frm").style.display="none"
}else{
switchPoint.innerText=3
document.all("frm").style.display=""
}}
</SCRIPT>
<TABLE height="100%" cellSpacing=0 cellPadding=0 width="100%" border=0>
<TR>
<TD id=frm vAlign=center noWrap align=middle><IFRAME
style="Z-INDEX: 2; VISIBILITY: inherit; WIDTH: 150px; HEIGHT: 100%"
name=rijcm src="left.asp"
frameBorder=0>rijcm</IFRAME></TD>
<TD width=10 bgColor=#4397c5>
<TABLE height="100%" cellSpacing=0 cellPadding=0 border=0>
<TBODY>
<TR>
<TD style="HEIGHT: 100%" onclick=switchbar()><FONT
style="FONT-SIZE: 9pt; CURSOR: hand; COLOR: white; FONT-FAMILY: Webdings"><SPAN
id=switchPoint>3</SPAN> </FONT></TR></TBODY></TABLE></TD>
<TD width="100%">
<IFRAME id=main style="Z-INDEX: 1; VISIBILITY: inherit; WIDTH: 100%; HEIGHT: 100%"
name=main src="bigsmall.asp" frameBorder=0 scrolling=yes>rijcm</IFRAME>
</TD>
</TR></TABLE>
</html>