left margine is not working properly in ajax tab cotrol.

I'm using ajax tab control and and trying to set left margine to 100px. but the tabs are appearing like this-       HomeProfileAboutmeProjectContact

Please help where I'm doing wrong?

<ajax:TabContainer ID="TabContainer1" runat="server" ActiveTabIndex="0"
                    Width="1119px" Height="373px" CssClass="tab"><ajax:TabPanel runat="server" HeaderText="TabPanel1" ID="TabPanel1"><HeaderTemplate>
                            Home</HeaderTemplate></ajax:TabPanel>

<styletype="text/css">

      .tab
        {
            position:relative; 
            margin-left:100px;
        }
    </style>