Server Error in my Webpage?

Question

Parser Error Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately.

Parser Error Message: System.Web.UI.HtmlControls.HtmlTableCellCollection must have items of type 'System.Web.UI.HtmlControls.HtmlTableCell'. 'p' is of type 'System.Web.UI.HtmlControls.HtmlGenericControl'.
MY CODE IS LIKE:
<table id="main" runat="server">
<tr>
<td>
<p> My Docs </p>
</td>
</tr>
</table>
In this if delete that ID and runat = Server tag it will work fine...
Please tell me, how can i solve this.