Check/Uncheck checkboxes in GridView using JavaScript

The question regarding how to check/uncheck CheckBoxes within a GridView control using JavaScript has been asked many times. Here is a quick reference you can follow.
First we have the .aspx markup.

<script type="text/javascript">

    function SelectAll(id) {

        var frm = document.forms[0];

        for (i=0;i<frm.elements.length;i++) {

            if (frm.elements[i].type == "checkbox") {

                frm.elements[i].checked = document.getElementById(id).checked;

            }

        }

    } 

</script>

<!-- assuming that SqlDataSource1 is the datasource for my GridView -->

<asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1" Width="400px">

    <Columns>

        <asp:TemplateField>

            <AlternatingItemTemplate>

                <asp:CheckBox ID="CheckBox1" runat="server" />

            </AlternatingItemTemplate>

            <ItemTemplate>

                <asp:CheckBox ID="CheckBox1" runat="server" />

            </ItemTemplate>

            <HeaderTemplate>

                <asp:CheckBox ID="cbSelectAll" runat="server" Text="Select All" />

            </HeaderTemplate>

            <HeaderStyle HorizontalAlign="Left" />

            <ItemStyle HorizontalAlign="Left" />

        </asp:TemplateField>

    </Columns>

</asp:GridView>

Next we have the code-behind in both VB and C#
VB

Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound

    If (e.Row.RowType = DataControlRowType.Header) Then

        'adding an attribute for onclick event on the check box in the header

        'and passing the ClientID of the Select All checkbox

        DirectCast(e.Row.FindControl("cbSelectAll"), CheckBox).Attributes.Add("onclick", "javascript:SelectAll('" & _

            DirectCast(e.Row.FindControl("cbSelectAll"), CheckBox).ClientID & "')")

    End If

End Sub

C#

protected void GridView1_RowDataBound(object sender, System.Web.UI.WebControls.GridViewRowEventArgs e) {

    if (e.Row.RowType == DataControlRowType.Header) {

        //adding an attribute for onclick event on the check box in the header

        //and passing the ClientID of the Select All checkbox

        ((CheckBox)e.Row.FindControl("cbSelectAll")).Attributes.Add("onclick", "javascript:SelectAll('" + ((CheckBox)e.Row.FindControl("cbSelectAll")).ClientID + "')");

    }

}

The example above is fantastic, but there are a couple things that could be improved.

1. The JavaScript Pseudo Protocol (Javascript:your method here) should be avoided, it's a fragment from the old Netscape days. Today there are better alternatives
2. In this case we probably don't need the server-side portion altogether.

An excerpt about the JavaScript Pseudo Protocol:

"The javascript: pseudo-protocol should not be used in event handlers like onclick. It should only be used in attributes that contain a URL, for example in the href attribute of <a> elements and the action attribute of <form> elements. You can also use it to make bookmarlets." - Common JavaScript Mistakes

Another solution the .aspx markup: 

<script type="text/javascript">

    // Let's use a lowercase function name to keep with JavaScript conventions

    function selectAll(invoker) {

        // Since ASP.NET checkboxes are really HTML input elements

        //  let's get all the inputs

        var inputElements = document.getElementsByTagName('input');

        for (var i = 0 ; i < inputElements.length ; i++) {

            var myElement = inputElements[i];

            // Filter through the input types looking for checkboxes

            if (myElement.type === "checkbox") {

               // Use the invoker (our calling element) as the reference 

               //  for our checkbox status

                myElement.checked = invoker.checked;

            }

        }

    } 

</script>

<!-- assuming that SqlDataSource1 is the datasource for my GridView -->

<asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1">

    <Columns>

        <asp:TemplateField>

            <AlternatingItemTemplate>

                <asp:CheckBox ID="CheckBox1" runat="server" />

            </AlternatingItemTemplate>

            <ItemTemplate>

                <asp:CheckBox ID="CheckBox1" runat="server" />

            </ItemTemplate>

            <HeaderTemplate>

                <asp:CheckBox ID="cbSelectAll" runat="server" Text="Select All" OnClick="selectAll(this)" />

            </HeaderTemplate>

            <HeaderStyle HorizontalAlign="Left" />

            <ItemStyle HorizontalAlign="Left" />

        </asp:TemplateField>

    </Columns>

</asp:GridView>