CSS: Aligning form fields on a page

In the following example, I have used ASP.NET controls as I have lifted this from a project I have been working on.
If you are not familiar with ASP.NET, when the browser renders these server controls, the controls are rendered down to simple HTML tags:

label (asp:Label)
input (asp:TextBox)
span (asp:RequiredFieldValidator))


HTML/ASP.NET Code

<fieldset class="regForm">

<div class="field">

    <asp:Label ID="lblFirstName" AssociatedControlID="txtFirstName" runat="server" Text="Firstname" />

    <asp:TextBox ID="txtFirstName" runat="server" />

    <asp:RequiredFieldValidator ID="rfvFirstName" runat="server" ControlToValidate="txtFirstName" SetFocusOnError="True" ValidationGroup="vgRegister" ErrorMessage="*" />

</div>

<div class="field">

    <asp:Label ID="lblSurname" AssociatedControlID="txtSurname" runat="server" Text="Surname" />

    <asp:TextBox ID="txtSurname" runat="server" />

    <asp:RequiredFieldValidator ID="rfvSurname" runat="server" ControlToValidate="txtSurname" SetFocusOnError="True" ValidationGroup="vgRegister" ErrorMessage="*" />

</div>

<div class="field">

    <asp:Label ID="lblEmail" AssociatedControlID="txtEmailAddress" runat="server" Text="Email" />

    <asp:TextBox ID="txtEmailAddress" runat="server" />

    <asp:RequiredFieldValidator ID="rfvEmail" runat="server" ControlToValidate="txtEmailAddress" SetFocusOnError="True" ValidationGroup="vgRegister" ErrorMessage="*" />

</div>

</fieldset>

CSS Code

fieldset.regForm div {

    clear: both;

    padding-top:0.2em;

}

fieldset.regForm label {

    display:inline;

    padding-top:0.2em;

    text-align:right;

    margin-right:0.5em;

    float:left;

    width:25%;

}