<asp:RequiredFieldValidator ID="RequiredFieldValidator16" runat="server" ControlToValidate="fck" Display="Dynamic" EnableClientScript="False" ErrorMessage="還沒有填寫內容"></asp:RequiredFieldValidator>

//Fck非空驗證
var oEditer;
function FckValidate(source, arguments)
{
var value = oEditer.GetXHTML(true);
if($.trim(value) == '')
{
arguments.IsValid = false;
}
else
{
arguments.IsValid = true;
}
}
function FCKeditor_OnComplete(editorInstance)
{
oEditer = editorInstance;
}

<asp:CustomValidator ID="CustomValidator1" runat="server" Display="Dynamic" ErrorMessage="沒有填寫" ClientValidationFunction="validTitle" OnServerValidate="ValidFck" ControlToValidate="fck"></asp:CustomValidator>