delete file error

[Michele]

hi, when i delete file this is the error

Eccezione non gestita alla riga 6, colonna 74203 in http://localhost:22266/Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=RadScriptManager1_TSM&compress=1&_TSM_CombinedScripts_=;;System.Web.Extensions,+Version=4.0.0.0,+Culture=neutral,+PublicKeyToken=31bf3856ad364e35:it-IT:c9cbdec3-c810-4e87-846c-fb25a7c08002:ea597d4b:b25378d2;Telerik.Web.UI:it-IT:df833b2e-28ee-45e7-8320-6f2a9cb883d7:16e4e7cd:f7645509:22a6274a:ed16cbdc:86526ba7:874f8ea2:2003d0b8:24ee1bba:e330518b:1e771326:c8618e41:fc0998fb:f46195d3:19620875:490a9d4e:bd8f85e4:e4f8f289:a7e79140:39040b5c:11a04f7e:e524c98b:58366029:ddbfcb67:7938962c:a585d0d4:7165f74:a44b89c4:f9b9258:aa288e2d:b7778d6c:e085fe68

0x800a138f - Errore di run-time di JavaScript: Impossibile impostare la proprietà 'control' di un riferimento nullo o non definito

you  can help me?
tnx

[Michele]

ok solved
Bye