# use existing instance if Excel is already running
	unless (defined $excel)
	{
		eval 
		{
			$excel = Win32::OLE->GetActiveObject('Excel.Application')
		};
		die "Excel not installed" if $@;
	}
	
	unless (defined $excel) 
	{
	    $excel = Win32::OLE->new('Excel.Application', 'Quit')
			    or die "Oops, cannot start Excel";
	}
	#to avoid excessive dialogs when saving in non-Excel format
	$excel->{DisplayAlerts} = 0;