Select Item DropDownList in GridView -Object reference not set to an instance of an object.

I have a dropdownlist attached to a cell when edit is selected.  I am using the following code to populate the drop down list with the value that is on the row.

dlBU.Items.FindByValue((e.Row.FindControl("lblBU") as Label).Text).Selected = true;

This works famously when I have a value in the cell.  It fails when the cell has not yet been populated.  Is there an if then clause that if the value of e.Row.findcontrol("lblBU") is null no default value?