function DoubleSize() {
nstv.width=eval(nstv.width)*2;
nstv.height=(eval(nstv.height)*2)-120;
nstv.DisplaySize=4;
if(eval(nstv.width>320)) self.resizeTo(820,650);
if (nstv.height == 480) self.resizeTo (650, 650);
if (nstv.height == 408) self.resizeTo (530, 580);
candouble = 0;}
function DefaultSize() {
nstv.width=eval(nstv.width) / 2;
nstv.height=(eval(nstv.height)+120) / 2;
nstv.DisplaySize=0;
self.resizeTo(500,528);
candouble = 1;
}
<object classid="CLSID:22d6f312-b0f6-11d0-94ab-0080c74c7e95"
codebase="http://activex.microsoft.com/activex/controls/mplayer/en/nsmp2inf.cab#Version=5,1,52,701"
height="228" id="nstv" style="left: 0px; top: 0px; border: 7px none rgb(192,192,192)"
type="application/x-oleobject" width="272"
standby="Loading Microsoft Windows Media Player components...">
nstv.width=eval(nstv.width)*2;
nstv.height=(eval(nstv.height)*2)-120;
nstv.DisplaySize=4;
if(eval(nstv.width>320)) self.resizeTo(820,650);
if (nstv.height == 480) self.resizeTo (650, 650);
if (nstv.height == 408) self.resizeTo (530, 580);
candouble = 0;}
function DefaultSize() {
nstv.width=eval(nstv.width) / 2;
nstv.height=(eval(nstv.height)+120) / 2;
nstv.DisplaySize=0;
self.resizeTo(500,528);
candouble = 1;
}
<object classid="CLSID:22d6f312-b0f6-11d0-94ab-0080c74c7e95"
codebase="http://activex.microsoft.com/activex/controls/mplayer/en/nsmp2inf.cab#Version=5,1,52,701"
height="228" id="nstv" style="left: 0px; top: 0px; border: 7px none rgb(192,192,192)"
type="application/x-oleobject" width="272"
standby="Loading Microsoft Windows Media Player components...">
<span id=zoom><input onclick="myfunction()" type=button value="放大"></span>
<script language=javascript>
function myfunction(){
document.all.NSOPlay.DisplaySize=2;
document.all('zoom').innerHTML="<input onclick=\"myfunction1()\" type=button value=\"缩小\">"
}
function myfunction1(){
document.all.NSOPlay.DisplaySize=4;
document.all('zoom').innerHTML="<input onclick=\"myfunction()\" type=button value=\"放大\">"
}
</script>