ASP.Net RadioButton TabIndex not working with GroupName

I have 2 radio button with same group name, i used tabindex in both. Whenever i am using tab to focus on fields in my form for radio button it is focusing on checked radio button only not on unchecked radio button. I used div and put tabindex also but it is not focusing on radio button it is focusing on div i mean highlighting border of div on focus. 

below i am attaching code of my radiobuttons:

<td style="font-family:Arial, Helvetica, sans-serif" class="auto-style25" colspan="3">
    <asp:RadioButton ID="rdlaborhourly" runat="server" Text="Hourly" GroupName="labor" Checked="true"
        OnCheckedChanged="rdlaborhourly_CheckedChanged" AutoPostBack="true" TabIndex="14" />
    <asp:RadioButton ID="rdlaborsalary" runat="server" Text="Salary" GroupName="labor"
        OnCheckedChanged="rdlaborsalary_CheckedChanged" AutoPostBack="true" TabIndex="15"/>
</td>

i want to focus on radio button. plz help me out as soon as possible.