我想要在页面中垂直居中一个弹窗。我在谷歌上搜索过很多资料,但都没有找到有用的东西。这是我的代码:
function inactive(id, ths) {
$("#confirmation").modal("show");
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="modal fade bs-example-modal-sm" id="confirmation" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel">
<div class="modal-dialog modal-sm" role="document">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span>
</button>
<h4 class="modal-title">Are you sure you want to inactivate it?</h4>
</div>
<div class="modal-body">
<div class="form-group">
<input type="text" class="form-control" name="captcha" id="cval" placeholder="enter captcha">
</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">No</button>
<button type="button" class="btn btn-primary" id="yes">Yes</button>
</div>
</div>
</div>
</div>
如何垂直居中?