How to make nivo slider full page width?

Server Error in '/' Application.

The "RenderSection" method has already been called for the section named "slider". 
  Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

 Exception Details: System.Web.HttpException: The "RenderSection" method has already been called for the section named "slider".

Source Error: 



Line 39: @if (IsSectionDefined("slider"))
Line 40: {
Line 41:     @RenderSection("slider")
Line 42: }
Line 43: <div class="columns-wrapper clearer">
 

@{
    Layout = "~/Views/Shared/_Root.cshtml";
}
@{
    //current category ID
    int currentCategoryId = 0;
    if (Url.RequestContext.RouteData.Values["controller"].ToString().Equals("catalog", StringComparison.InvariantCultureIgnoreCase) &&
        Url.RequestContext.RouteData.Values["action"].ToString().Equals("category", StringComparison.InvariantCultureIgnoreCase))
    {
        currentCategoryId = Convert.ToInt32(Url.RequestContext.RouteData.Values["categoryId"].ToString());
    }


    //current manufacturer ID
    int currentManufacturerId = 0;
    if (Url.RequestContext.RouteData.Values["controller"].ToString().Equals("catalog", StringComparison.InvariantCultureIgnoreCase) &&
        Url.RequestContext.RouteData.Values["action"].ToString().Equals("manufacturer", StringComparison.InvariantCultureIgnoreCase))
    {
        currentManufacturerId = Convert.ToInt32(Url.RequestContext.RouteData.Values["manufacturerId"].ToString());
    }


    //current product ID
    int currentProductId = 0;
    if (Url.RequestContext.RouteData.Values["controller"].ToString().Equals("product", StringComparison.InvariantCultureIgnoreCase) &&
        Url.RequestContext.RouteData.Values["action"].ToString().Equals("productdetails", StringComparison.InvariantCultureIgnoreCase))
    {
        currentProductId = Convert.ToInt32(Url.RequestContext.RouteData.Values["productId"].ToString());
    }
}
@if (IsSectionDefined("slider"))
{
    @RenderSection("slider")
}
<div class="columns-wrapper clearer">
    <div class="leftside-3">
        @if (IsSectionDefined("left"))
        {
            @RenderSection("left")
        }
        else
        {
            @Html.Widget("left_side_column_before")
            @Html.Action("CategoryNavigation", "Catalog", new { currentCategoryId = currentCategoryId, currentProductId = currentProductId })
            @Html.Widget("left_side_column_after_category_navigation")
            @Html.Action("ManufacturerNavigation", "Catalog", new { currentManufacturerId = currentManufacturerId })
            @Html.Action("VendorNavigation", "Catalog")
            @Html.Action("PopularProductTags", "Catalog")
            @Html.Action("PollBlock", "Poll", new { systemKeyword = "LeftColumnPoll" })
            @Html.Widget("left_side_column_after")
        }
    </div>
    <div class="rightside-3">
        @if (IsSectionDefined("right"))
        {
            @RenderSection("right")
        }
        else
        {
            @Html.Widget("right_side_column_before")
            @Html.Action("NewsletterBox", "Newsletter")
            @Html.Action("RecentlyViewedProductsBlock", "Product", new { productThumbPictureSize = 32 })
            @Html.Action("PollBlock", "Poll", new { systemKeyword = "RightColumnPoll" })
            @Html.Widget("right_side_column_after")
        }
    </div>
    <div class="center-3">
        @Html.Widget("main_column_before")
        @RenderBody()
        @Html.Widget("main_column_after")
    </div>
</div>

@{
    Layout = "~/Views/Shared/_Root.cshtml";
}
<div class="columns-wrapper clearer">
    <div class="center-1">
        @Html.Widget("main_column_before")
        @RenderBody()
        @Html.Widget("main_column_after")
    </div>
</div>

@{
    Layout = "~/Views/Shared/_Root.cshtml";
}
@{
    //current category ID
    int currentCategoryId = 0;
    if (Url.RequestContext.RouteData.Values["controller"].ToString().Equals("catalog", StringComparison.InvariantCultureIgnoreCase) &&
        Url.RequestContext.RouteData.Values["action"].ToString().Equals("category", StringComparison.InvariantCultureIgnoreCase))
    {
        currentCategoryId = Convert.ToInt32(Url.RequestContext.RouteData.Values["categoryId"].ToString());
    }


    //current manufacturer ID
    int currentManufacturerId = 0;
    if (Url.RequestContext.RouteData.Values["controller"].ToString().Equals("catalog", StringComparison.InvariantCultureIgnoreCase) &&
        Url.RequestContext.RouteData.Values["action"].ToString().Equals("manufacturer", StringComparison.InvariantCultureIgnoreCase))
    {
        currentManufacturerId = Convert.ToInt32(Url.RequestContext.RouteData.Values["manufacturerId"].ToString());
    }


    //current product ID
    int currentProductId = 0;
    if (Url.RequestContext.RouteData.Values["controller"].ToString().Equals("product", StringComparison.InvariantCultureIgnoreCase) &&
        Url.RequestContext.RouteData.Values["action"].ToString().Equals("productdetails", StringComparison.InvariantCultureIgnoreCase))
    {
        currentProductId = Convert.ToInt32(Url.RequestContext.RouteData.Values["productId"].ToString());
    }
}
<div class="columns-wrapper clearer">
    <div class="side-2">
        @if (IsSectionDefined("left"))
        {
            @RenderSection("left")
        }
        else
        {
            @Html.Widget("left_side_column_before")
            @Html.Action("CategoryNavigation", "Catalog", new { currentCategoryId = currentCategoryId, currentProductId = currentProductId })
            @Html.Widget("left_side_column_after_category_navigation")
            @Html.Action("ManufacturerNavigation", "Catalog", new { currentManufacturerId = currentManufacturerId })
            @Html.Action("VendorNavigation", "Catalog")
            @Html.Action("NewsletterBox", "Newsletter")
            @Html.Widget("left_side_column_after")
        }
    </div>
    <div class="center-2">
        @Html.Widget("main_column_before")
        @RenderBody()
        @Html.Widget("main_column_after")
    </div>
</div>