private void button2_Click_1(object sender, EventArgs e)
 {
     if (param == null || param.IsDisposed)
     {
         param           = new Parameter_Extraction_PDF();
         param.MdiParent = this;
         param.Show();
     }
     else
     {
         param.WindowState = FormWindowState.Maximized;
         param.Activate();
     }
 }
 private void extractingPDFToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (param == null || param.IsDisposed)
     {
         param           = new Parameter_Extraction_PDF();
         param.MdiParent = this;
         param.Show();
     }
     else
     {
         param.WindowState = FormWindowState.Maximized;
         param.Activate();
     }
 }