Collection - Out of boundaries [66000-34]

hello all can someone please help me with this problem

i have created a UFO with data Sources in it and i have a choose from list i need to take the value when the user selects a row from the CFL and put it in a text box i used this code:

SAPbouiCOM.Form oForm = Application.SBO_Application.Forms.Item(FormUID); SAPbouiCOM.UserDataSource ClaimServNumber = oForm.DataSources.UserDataSources.Item("Item_1");

oForm.DataSources.UserDataSources.Item(ClaimServNumber).ValueEx = oRecordset.Fields.Item("U_ClaimNo").Value;

the following error occurs:

Collection - Out of boundaries [66000-34]

thank you.