底部操作表高度

在底面的弹出框内 我想要把弹出框的高度变高一点 内容增多后 侧面就会产生滚动条 不会增加高度

本人新学习 请各位大神赐教

<div id="sheet" class="mui-popover mui-popover-bottom mui-popover-action ">  

        <ul class="mui-table-view ">  
            <li class="mui-table-view-cell " style="text-align: center;">  
                <div class="">  
                    <a id="cancel" class=" mui-icon mui-icon-closeempty mui-pull-left"></a>  
                    <span style="font-size: 14px; font-weight: bold;color: black;">付款详情</span>  
                    <a class=" mui-icon mui-icon-help mui-pull-right" style="font-size: 19px;"></a>  
                </div>  
            </li>  
            <li class="mui-table-view-cell">  
                <div class="mui-row text-fukuan">  
                    <  
                </div>  
            </li>  
            <li class="mui-table-view-cell">  
                <div class="mui-row text-fukuan">  

            </div>  
          </li>  
          <li class="mui-table-view-cell" style="height: 250px; position: relative;">  
                <div class="mui-row text-colol-size" style="margin-top: 10px;" >  

                </div>    
                <span class="" style="position: absolute;bottom: 0px;left: 15px;right: 15px;">  
                    <button id="surepay" type="button" class="mui-btn mui-btn-blue mui-btn-block">确认付款</button>   
                </span>  
          </li>         
       </ul>  
      </div>