clear form values after submission ajax

I am using the following script for validate my contact form.

//submission scripts
  $('.contactForm').submit( function(){
        //statements to validate the form   
        var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
        var email = document.getElementById('e-mail');
        if (!filter.test(email.value)) {
            $('.email-missing').show();
        } else {$('.email-missing').hide();}
        if (document.cform.name.value == "") {
            $('.name-missing').show();
        } else {$('.name-missing').hide();} 

        if (document.cform.phone.value == "") {
            $('.phone-missing').show();
        } 
        else if(isNaN(document.cform.phone.value)){
        $('.phone-missing').show();
        }
        else {$('.phone-missing').hide();}  

        if (document.cform.message.value == "") {
            $('.message-missing').show();
        } else {$('.message-missing').hide();}  

        if ((document.cform.name.value == "") || (!filter.test(email.value)) || (document.cform.message.value == "") || isNaN(document.cform.phone.value)){
            return false;
        } 

        if ((document.cform.name.value != "") && (filter.test(email.value)) && (document.cform.message.value != "")) {
            //hide the form
            //$('.contactForm').hide();

            //show the loading bar
            $('.loader').append($('.bar'));
            $('.bar').css({display:'block'});

        /*document.cform.name.value = '';
        document.cform.e-mail.value = '';
        document.cform.phone.value = '';
        document.cform.message.value = '';*/

            //send the ajax request
            $.post('mail.php',{name:$('#name').val(),
                              email:$('#e-mail').val(),
                              phone:$('#phone').val(),
                              message:$('#message').val()},

            //return the data
            function(data){