procedure TCLFYTJMAIN.ClearColumn(_oGrid:TDataGrid);
var
i:integer;
nCount,nNum:integer;
oColumn:TDataGridColumn;
sName:string;
begin
nCount := _oGrid.ColumnCount;
for i:= 1 to nCount do
begin
sName := 'Field' + SysUtils.IntToStr(i);
oColumn := TDataGridColumn(_oGrid.ColumnByName(sName));
oColumn.Free();
_oGrid.Refresh();
end;