<form name="aa" action="aa.asp" method="post" target="_blank">
<input type="checkbox" name="aa" value="aa">
<input type="checkbox" name="aa" value="aa">
<input type="checkbox" name="aa" value="aa">
<input type="submit" name="ok" >
</form>
<input type="checkbox" name="aa" value="aa">
<input type="checkbox" name="aa" value="aa">
<input type="checkbox" name="aa" value="aa">
<input type="submit" name="ok" >
</form>
<input type="checkbox" name="aa" value="aa">
<input type="checkbox" name="aa" value="aa">
<input type="checkbox" name="aa" value="aa">
<input type="submit" name="ok" >
</form>