DateTime From Database Entry

Hi, I know this is probably very simple but I am pretty new to this and have tried looking but cant seem to get the search criteria right.
I have  a database with a storeDate field which is of shortdatetime type. I am connecting to the database (MSSQL)  via a stored procedure and returning all the records. I then use the code
 
 foreach (DataRow dr in ds.Tables[0].Rows)
  {
      DateTime dtTo = DateTime.Now;
      DateTime dtFrom = DateTime.Parse(dr["storeDate"].ToString());
      TimeSpan diff = dtTo.Subtract(dtFrom);
  }
 I am basically trying to find out the age of the database entry by subtracting it from the current DateTime so i can delete records over a certain age. The problem (at least one of them!) is retrieving the "storeDate" object from the database and storing it in the dtFrom object. I have tried just assigning it directly as dtFrom = dr["storeDate"] and various other methods but I just don't know enough to assign it!  Can anyone help me with this or spot any other mistakes in this process of removing old files automatically.
 
Greatly Appreciated,Sean.