Issue Reading Content of Control for Email
===

I have a simple ASCX control on a web page that renders data in a repeater. It also includes a  button that will email the content of that repeater on _Click.

The problem is I can't get the content of the div effectively.

    var sw = new System.IO.StringWriter();
    var hw = new HtmlTextWriter(sw);
    quotecontent.RenderControl(hw);

Returns this error:

    RegisterForEventValidation can only be called during Render();
    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.InvalidOperationException: RegisterForEventValidation can only be called during Render();
    
    Source Error:
    
    An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
    
    Stack Trace:
    
    
    [InvalidOperationException: RegisterForEventValidation can only be called during Render();]
       System.Web.UI.ClientScriptManager.RegisterForEventValidation(String uniqueId, String argument) +696
       System.Web.UI.HtmlControls.HtmlTextArea.RenderAttributes(HtmlTextWriter writer) +105
       System.Web.UI.HtmlControls.HtmlControl.RenderBeginTag(HtmlTextWriter writer) +57
       System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +27
       System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +246
       System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +42
       FurunoRapid.Controls.ShowQuote.<emailOK_Click>b__0() +341
       Microsoft.SharePoint.SPSecurity.CodeToRunElevatedWrapper(Object state) +73
       Microsoft.SharePoint.<>c__DisplayClass4.<RunWithElevatedPrivileges>b__2() +592
       Microsoft.SharePoint.Utilities.SecurityContext.RunAsProcess(CodeToRunElevated secureCode) +319
       Microsoft.SharePoint.SPSecurity.RunWithElevatedPrivileges(WaitCallback secureCode, Object param) +571
       Microsoft.SharePoint.SPSecurity.RunWithElevatedPrivileges(CodeToRunElevated secureCode) +135
       FurunoRapid.Controls.ShowQuote.emailOK_Click(Object sender, EventArgs e) +101
       System.Web.UI.WebControls.Button.OnClick(EventArgs e) +103
       System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +140
       System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +32
       System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3103
    
    
    Version Information: Microsoft .NET Framework Version:2.0.50727.4216; ASP.NET Version:2.0.50727.4209 

All of the posts I've seen dealing with this issue involve render a gridview (which I'm not) or loading an external ASCX (which I'm also not, the click event AND the element with the desired content for rendercontrol both live inside this ASCX)

The repeater renders content inside this div:

<div id="quotecontent" runat="server">

How do I safely get the content server side to email?

NOTE I cannot use enableEventValidaton = false, as I cannot modify the hose ASPX file. I need to run a command in server side code, or use an alternate method to retrieve the contents of the element.