<div style="width:100%; background-color:Aqua; text-align:center; vertical-align:middle; height:30px;">
<asp:ValidationSummary ID="ValidationSummary1" runat="server" HeaderText="Error" />
</div>
i dont want to show div element if has no error . i dont want to use js, just with asp controls !
use
height:auto; line-height:30px;instead ofheight:30px;