check detail view null fields before inserting

Question

I have detail view in asp.net from which i am inserting data to DB.Here i want to check before insert if any field is null or not and if null then don't insert otherwise insert into db i have tried the following code but it doesn't working

protected void DetailsView1_ItemInserting(object sender, DetailsViewInsertEventArgs e)
    {
     string unt = (string)e.Values["UNT_COD"];
     if (unt == "")
     {
         e.Cancel = true;  
     }
    }

Through this code i am not achieving my purpose plz any one help me to find out the way to check

Answer 1

string unt = e.Values["UNT_COD"]+"";
 if (unt == "")
 {
     e.Cancel = true;  
 }