!!!Listing18

	FormType *formP;
	MemHandle h;
	char *FieldData;
	Int16 Negative;
	double Koord;
	Int8 err;

	formP = FrmGetFormPtr( FormPREFERENCES );

	if ( formP ) {
// storing the field for geographic height
		h = FldGetTextHandle( FrmGetObjectPtr( formP,
			FrmGetObjectIndex( formP, FieldNS) ) );
		FieldData = (char *) MemHandleLock( h );
		err = LW_StrToDouble( FieldData, &Koord );
		if ( ! err )
			PrefRec.GeoHeight = Koord;
		MemHandleUnlock( h );
