Login Alignment

So my problem is, this code doesn't display like I think it should while using FireFox. For some reason, the alignment is off (to the left) and when I try to add (aligm="center"/style="left:300px") some type of position to a tag, it begins to look right in FireFox but blows up Internet Explorer.

What's the cause of this? Any suggestions on a fix?

Code:

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<%@ Page Title="Log In" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
    CodeFile="Default.aspx.cs" Inherits="_Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
 
    <asp:Login ID="LoginUser" runat="server" EnableViewState="false"
        RenderOuterTable="false" DestinationPageUrl="~/Welcome.aspx">
        <LayoutTemplate>
            <span class="failureNotification">
                <%-- <asp:Literal ID="FailureText" runat="server"></asp:Literal> --%>
            </span>
            <asp:ValidationSummary ID="LoginUserValidationSummary" runat="server" CssClass="failureNotification"
                ValidationGroup="LoginUserValidationGroup" />
            <div class="accountInfo" >
                <fieldset class="login">
                    <legend>Account Information</legend>
                    <p>
                        <asp:Label ID="UserNameLabel" runat="server" AssociatedControlID="UserName">Username:</asp:Label>
                        <asp:TextBox ID="UserName" runat="server" CssClass="textEntry"></asp:TextBox>
                        <asp:RequiredFieldValidator ID="UserNameRequired" runat="server" ControlToValidate="UserName"
                            CssClass="failureNotification" ErrorMessage="User Name is required." ToolTip="User Name is required."
                            ValidationGroup="LoginUserValidationGroup">*</asp:RequiredFieldValidator>
                    </p>
                    <p>
                        <asp:Label ID="PasswordLabel" runat="server" AssociatedControlID="Password">Password:</asp:Label>
                        <asp:TextBox ID="Password" runat="server" CssClass="passwordEntry" TextMode="Password"></asp:TextBox>
                        <asp:RequiredFieldValidator ID="PasswordRequired" runat="server" ControlToValidate="Password"
                            CssClass="failureNotification" ErrorMessage="Password is required." ToolTip="Password is required."
                            ValidationGroup="LoginUserValidationGroup">*</asp:RequiredFieldValidator>
                    </p>
                  <%-- <p>
                        <asp:CheckBox ID="RememberMe" runat="server" />
                        <asp:Label ID="RememberMeLabel" runat="server" AssociatedControlID="RememberMe" CssClass="inline">Keep me logged in</asp:Label>
                    </p>--%>
                    <p>
                        <asp:HyperLink ID="HyperLink1" runat="server"
                            NavigateUrl="~/RetrieveLogin.aspx">Forgot your password/User ID?</asp:HyperLink>
                    </p>
                </fieldset>
                <p class="submitButton">
                    <asp:Button ID="LoginButton" runat="server" CommandName="Login" Text="Log In"
                        ValidationGroup="LoginUserValidationGroup" onclick="LoginButton_Click" />
                </p>
            </div>
        </LayoutTemplate>
    </asp:Login>
</asp:Content>

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