javascript multibox 全选

function allselect() 
{ 
try{ 
var checkedcount=0; 
for(var i=0;i<form1.orgIds.length;i++) 
{ 
if(form1.orgIds[i].checked) 
checkedcount++; 
} if(checkedcount==form1.orgIds.length) 
{ 
for(var i=0;i<form1.orgIds.length;i++) 
{ 
form1.orgIds[i].checked=false; 
} 
} 
else 
{ 
for(var i=0;i<form1.orgIds.length;i++) 
{ 
form1.orgIds[i].checked=true; 
} 
} 
if(form1.orgIds.checked==true) 
form1.orgIds.checked=false; 
else 
form1.orgIds.checked=true; 
}catch(ex){} 
}

<SPAN style="CURSOR:hand" onclick="allselect()">(全选)</SPAN> 
<logic:iterate id="result" name="zclist" indexId="ind"> 
<html:multibox property="orgIds"><bean:write name="result" property="someProperty"/></html:multibox> 
</logic:iterate>