$(function(){	$('.kampeerplaats').hide();    
	$('.paaltent').hide();    
	$('.paalcottage').hide();   
	$('.paalcasa').hide();    
	$('.trekkershut').hide();   

	$('input[name=kampeerplaats]').click(expandForm); 
	$('input[name=paaltent]').click(expandForm);  
	$('input[name=paalcottage]').click(expandForm);  
	$('input[name=paalcasa]').click(expandForm);   
	$('input[name=trekkershut]').click(expandForm);

});

var expandForm = function(){   

 form = $('div.' + this.name);    
this.checked ? form.show() : form.hide();


}