RadControlHelper.ExtractComboBoxValue does not work

[Sub]

Hi,

I followed the sample from the online help under http://www.telerik.com/help/aspnet-ajax/mvc-getting-combobox-value.html.
When I tried to get the value of the RadComboBox in my project it throws the folIowing error: Can you provide an working sample for a reference please??

Value cannot be null.
Parameter name: input

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.ArgumentNullException: Value cannot be null.
Parameter name: input

Source Error:

Line 57: { Line 58: var clientStateString = ExtractStringValue(request, comboboxId + "_ClientState"); Line 59: var clientState = new JavaScriptSerializer().Deserialize<RadComboBoxClientState>(clientStateString);Line 60: return clientState.Value; Line 61: }

[Atanas Korchev]

Hi Sub,

Please find attached a working page demonstrating how to use that method.

Regards,
Albert
the Telerik team

Check out Telerik Trainer , the state of the art learning tool for Telerik products.

[estebangamez]

Albert

I used the two files attached to this question but is still giving problems.I'm getting the classic  RadScriptManager must be placed inside a form.However i placing the control inside a contentHolder located in the head section of a website.The header contains the runat="server" property.I been trying to place the script manager in many places but with no positive results.Is there any way you can send me the entire project ? It's fine if you exclude telerik references but I need to see what I'm doing wrong.

Thanks in advance
Esteban