jquery form submission

Use jQuery+JSON combination something like this:

test.php:

<script type="text/javascript" src="jquery-1.4.2.js"></script>
<script type="text/javascript" src="jsFile.js"></script>

<form action='_test.php' method='post' class='ajaxform'>
 <input type='text' name='txt' value='Test Text'>
 <input type='submit' value='submit'>
</form>

<div id='testDiv'></div>

_test.php:

<?php
      // Code here to deal with your form submitted data.
      $arr = array( 'testDiv' => 'Form is successfully submitted.' );
      echo json_encode( $arr );
?>

jsFile.js:

jQuery(document).ready(function(){

    jQuery('.ajaxform').submit( function() {

        $.ajax({
            url     : $(this).attr('action'),
            type    : $(this).attr('method'),
            dataType: 'json',
            data    : $(this).serialize(),
            success : function( data ) {
                        for(var id in data) {
                            jQuery('#' + id).html( data[id] );
                        }
                      }
        });

        return false;
    });

});

OR:

You can use jQuery Form Plugin