var form_error = 0;

	function submit_this(form) {
	
		validate_form();
		
		if (!form_error) {
			form.submit();
		} else {
			return false;
		}
	}

	function validate_checkboxes() {
	
		form_error = 1;
		var arr_checkboxes = document.getElementById("checkboxes").getElementsByTagName("input");
		for (var i=0;i<arr_checkboxes.length;i++) {
			if (arr_checkboxes[i].checked) {
				form_error = 0;
				return true;
			}
		}
		return false;
	}
	
	function validate_postcode() {
		
		form_error = 1;
		var post_code = document.getElementById('postcode').value;
		if (checkPostCode(post_code)) {
			document.getElementById('postcode').value = checkPostCode(post_code);
			form_error = 0;
			return true;
		}
		return false;
	}