By default the fieldset is opened or expanded at start. Click on its legend to close or collapse it.
The code is simply like below
$('#fieldset1').coolfieldset();
If we want the fieldset to be closed or collapsed at start, just add {collapsed:true} as the argument.
$('#fieldset2').coolfieldset({collapsed:true});
You can also define the animation speed for the fieldset while collapsing or expanding by using speed option. Acceptable values are "fast", "medium", "slow", or a number in millisecond.
$('#fieldset3').coolfieldset({speed:"fast"});
If you don't want to use animation effect, please use animation option and fill its value with false.
$('#fieldset4').coolfieldset({animation:false});