css th:hover to change background - color

i have table with below structure:

     <table class="cedvel">
            <caption>
                count:
                <%:Html.Encode(TempData["RowsCount"])%></caption>
     <thead>
                <tr>
                    <th id="thAfield1" class="field1,asc">
                        <span>field1</span><span id="spanAfield1" class="spanAscDesc">↑↓</span>
                    </th>
                    <th id="thfild2" class="field2,asc">
                        <span>field2</span> <span id="spanfield2" class="spanAscDesc">↑↓</span>
                    </th>
................................
     </thead>
            <tbody>
                <%if (Model.<----->.Count() > 0)
                  {
                      foreach (var abonent in Model.<---->)
                      {%>
                <tr>
                    <td>
                        data
                  开发者_如何学Python  </td>
                    <td>
                        data
                    </td>
................................
    </tr>
     <tr class="noData">
                    <td colspan="11">
                        no info
                    </td>
                </tr>
                <% }%>
            </tbody>
        </table>

now i want to change background - color when hovering on th. but can not do it. but simply i can change color when hovering on tr. but on th i can not.

table.cedvel th
{
    background-color: #c3dde0;
    background-image: url(../Content/SiteImages/1.png);
    border-width: 1px;
    padding: 8px;
    border-style: solid;
    border-color: #a9c6c9;
}
table.cedvel th:hover
{
    background-color: Red;
}

i simply setting background-image: none when hovering. here was my problem. when i hovered on it. it changed background color. but my pic. hided it.

Have a look at this fiddle : http://jsfiddle.net/jomanlk/Bcayc/ It works form e

You probably have an issue with your CSS.

table.cedvel th {
    background-color: #c3dde0;
    background-image: url(../Content/SiteImages/1.png);
}

table.cedvel th:hover {
    background-color: red;
    background-image: none;
}