[jQuery] newbie: unfold form on checkbutton

[jQuery] newbie: unfold form on checkbutton


Hello,
I need to make a dynamic form. This morning I found jquery and this
looks like the tool I need.
My first challenge is unfolding part of a form on a checked
checkbutton. The code I wrote does
not work. Can someone point me in the right direction?
<script type="text/javascript">
$(function() {
jQuery.fn.extend({
check: function() {
return this.each(function() { this.checked = true; });
},
uncheck: function() {
return this.each(function() { this.checked = false; });
}
});
$('a#period').click(function(){
if ($("input[@type=radio]").check() ==
true){
$('#showperiod').show();
} else {
$('#showperiod').hide();
}
});
});
</script>
The checkbox is in an anchor (id="period"), and the id that must be
unfolded is showperiod.
Thank you