bootstrap模态框字数字数

<!-- 按钮触发模态框 -->
<button class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal">开始演示模态框</button>
<!-- 模态框（Modal） -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
<h4 class="modal-title" id="myModalLabel">模态框（Modal）标题</h4>
</div>
<div class="modal-body">在这里添加一些文本</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>
<button type="button" class="btn btn-primary">提交更改</button>
</div>
</div><!-- /.modal-content -->
</div><!-- /.modal -->
</div>