Form validation with jQuery (and twitter bootstrap) http://testandheiberg.tumblr.com/post/60573208864/form-validation-with-jquery

main.js

jQuery.validator.setDefaults({
	errorPlacement: function(error, element) {
		// hide any previous help... this could be "not visible to others"
		$(element).closest('.controls').find('.help-inline').addClass('hidden');

		// if the input has a prepend or append element, put the validation msg after the parent div
		if ($(element).parent().hasClass('input-prepend') || $(element).parent().hasClass('input-append')) {
			error.insertAfter($(element).parent());		
		// else just place the validation message immediatly after the input
		}
		else if ($(element).attr('type') === 'checkbox') {
			$(element).closest('.controls').append(error);
		} else {
			error.insertAfter($(element));
		}
	},
	errorElement: "span", // contain the error msg in a small tag
	errorClass: "help-inline",
	highlight: function(element) {
		$(element).closest('.control-group').addClass('error'); // add the Bootstrap error class to the control group
	},
	success: function(element) {
		$(element).closest('.control-group').removeClass('error'); // remove the Boostrap error class from the control group
		$(element).closest('.controls').find('.help-inline').removeClass('hidden');
	}
});