<script>
    $(document).ready(function(){
        $("#write_btn").click(function(){
            if($("#comment").val()==""){
                alert('내용을 입력해주세요');
                $("#comment").focus();
                return false;
            }else{
                $("#write_action").submit();
            }
        });
    });
</script>

<?php foreach ($comment as $lt):
$http = "/image/comment/".$lt->id;
$attributes = array('id'=>'write_action_'.$lt->id,'class'=>'form_horizontal');
echo form_open($http,$attributes);

<textarea class="input-xlarge" id="comment_<?=$lt->id;?>" name="comment" rows="3">
</textarea>
<input type="hidden" name="id" value='<?=$lt->id;?>'>
<input type="hidden" name="name" value='<?=$this->uri->segment(1);?>'>
<button type="submit" id="write_btn_<?=$lt->id;?>">작성</button>
endforeach;?>