Update Query not working

hi can anyone tell me is there any syntactical error in the below Query. I used excel as DB

“update [Employee_Details$] set [Status]=’”+EmpDataTemplate(“Status_After_Successful_data_Extraction”).ToString+"’ where [Association ID]= ‘"+EmpRow(“Association ID”).ToString+"’"

its not throwing any error at the same time it updates null value in the column . but value exist in both the variable.

Please help…