<asp:DataList ID="DataList2">
<ItemTemplate>
........
<textarea id="item" runat="server" rows="7" class="textarea"
readonly="readonly">
</textarea>
</ItemTemplate>
</asp:DataList>

in your code behind file -

string comment="etc";
HtmlTextArea setrows = (HtmlTextArea)DataList1.Items[y].FindControl("commenthold");
setrows.Value = comment;//assign value in the textarea

this may be easy.but this will give you knowledge about how
you will access any html element from asp.net code behind
page.