SharePoint InputFormTextBox returns javascript error while changing its position

I have created one aspx page for implementing the edit comments of the form. For this I am using the SharePoint InputFormTextBox control. I have a total of 4 Divs each containing one InputFormTextBox, 2 hiddenfields and 3 buttons. Sample code of one div is shown below.

<div id="p0">        
    <asp:HiddenField ID="hSectionNamep0" runat="server" Value="Statement" />
    <asp:Button ID="btnUpp0" runat="server" Text="Up" OnClientClick="moveDiv('p0', 'up');  return false;" />&nbsp;
    <asp:Button ID="btnDownp0" runat="server" Text="Down" OnClientClick="moveDiv('p0', 'down');  return false;" />&nbsp;
    <asp:Button ID="btnDeletep0" runat="server" Text="Delete" OnClientClick="removeDiv('p0');  return false;" />&nbsp;
    <SharePoint:InputFormTextBox ID="Editor0" runat="server" Font-Names="verdana,arial,helvetica,sans-serif"
        Rows="10" RichTextMode="FullHtml" TextMode="MultiLine" RichText="true" CssClass="ms-rtelong">
    </SharePoint:InputFormTextBox>
    <asp:HiddenField ID="hdnp0" runat="server" Value="0" />
</div>

These same controls with different names are placed inside 3 other divs followed by the above div.

For changing the position, I am using this jquery method.

function moveDiv(id, direction) {

    var previous = getPrevDiv(id);
    var next = getNextDiv(id);

    if (direction == "up") {
        $("#" + previous.id).insertAfter("#" + id); 

    }
    else if (direction == "down") {

        $("#" + id).insertAfter("#" + next.id);
        }


    refreshButtons();


}

The getPrevDiv() and getNextDiv() as follows.

function getPrevDiv(id) {
    var children = $('#editors').children();
    if (children[0].id == id) {
        return null;
    }

    for (i in children) {
        if (children[i].id == id) {
            return children[i - 1];
        }
    }
}
function getNextDiv(id) {
    var children = $('#editors').children();

    for (var i = 0; i < children.length - 1; i++) {
        if (children[i].id == id) {
            return children[i + 1];
        }
    }

    return null;
}

All the positions of these Divs are changing correctly. But unfortunately, one extra InputFormTextBox with disabled toolbar is showing just below of the orginal control. While debugging the solution I am getting this error.

Microsoft JScript runtime error: Unable to set value of the property 'designMode': object is null or undefined

followed by some other error related with this same control. Please help me to resolve this issue.

Thanks in advance.