I have "displayNone" class in my HTML, in Jquery I add and remove it and it is working with FF and IE8, but I have problem with IE7 could you help me.
<tr id="tr<%=category %>_1_<% =message.MessageID.ToString() %>" class='<%= (firstCategory ? "" : "displayNone") %>'>
<td id="td<%=category %>_1_1_<% =message.MessageID.ToString() %>" rowspan="2">
<img id="imgEnv<% =message.MessageID.ToString() %>" src='../../Content/Images/envelope_<% =(newMessage ? "closed" : "open") %>.gif'
alt="message" />
</td>
<td class="text-align-right" rowspan="2">
<%= Html.CheckBox("chkMsg", false, new { @value= message.MessageID, @id = string.Format("chkMsg{0}", message.MessageID), @tabindex = "-1" })%>
</td>
</tr>
$('a[id*=lCateg]').click(function() {
var category = this.id.replace('lCateg', '');
if ($('#imgCateg' + category).attr('src').indexOf('plus.gif') >= 0) {
$('tr[id*=' + category + '_]').removeClass('displayNone');
$('#imgCateg' + category).attr('src', $('#imgCateg' + category).attr('src').replace('plus.gif', 'minus.gif'));
}