private void btnPrintA4_Click(object sender, EventArgs e) { Param.Paper = Param.PaperSize; FmSelectPrinter fm = new FmSelectPrinter(); if (fm.ShowDialog(this) == DialogResult.OK) { Param.PaperSize = "A4"; miPrintReceipt_Click(sender, (e)); Param.DevicePrinter = Param.Printer; Param.PaperSize = Param.Paper; } }