Update a Value From TEdit

I am attempting to update a table using a value that is displayed on a TEdit component. I am getting an access violation error.

Can someone tell me what I am doing wrong??

procedure TLoopBuilderForm.NewLoopButtonClick(Sender: TObject);

var Edit1 : TEdit ;

begin

PSQLQuery1.Close;{close the query}
//assign new SQL expression Monitor
PSQLQuery1.SQL.Clear;
PSQLQuery1.SQL.Add ('Update P_ID.Loops');
PSQLQuery1.SQL.Add ('Set IDW_Loop_ID = + LoopNumberEdit');
PSQLQuery1.SQL.Add ('Where P_ID.Loops.Loop_Name = :Loop_Name');
PSQLQuery1.ParamByName('LoopNumberEdit').Value := Edit1.Text;
PSQLQuery1.Execsql;

end;

Running Delphi 6 and PostgreSQL 8.2 on Win XP.

Bob