//javascript function

function submitComment(rowid, comment, event){
                if(event.keyCode == 13){
                    $.post('../resource/ajax.php', {addcomment:comment, rowId:rowid});3
                    alert('sent')
                }
             }

//html
<button id="deleteComment" name="deleteComment" value="<?php echo $comment['Id']; ?>" onclick="proceed()">X</button>


//php ajax

    if(isset($_POST['addcomment'])){

        $comment = $_POST['addcomment'];
        $Dbid = $_POST['rowId'];
        $user = $_SESSION['session_user'];
        $sql = "INSERT INTO Dcomment (Id, Username, Email, Comments, UDate, Dbid)  VALUES ('',  '$user', '', '$comment', CURRENT_TIMESTAMP, '$Dbid')";

        $result = mysql_query($sql);

    }