private void btnRSASignature_Click(object sender, EventArgs e)
 {
     if (!RSASigature.Visible)
     {
         RSASigature = new frmRSASignature();
         RSASigature.Show();
     }
     else
     {
         RSASigature.BringToFront();
     }
 }
 private void btnRSASignature_Click(object sender, EventArgs e)
 {
     if (!RSASignature.Visible)
     {
         RSASignature = new frmRSASignature();
         RSASignature.Show();
         if (txtSignedData.Text != "" && txtKey.Text != "")
         {
             RSASignature.setMessageAndKey(txtSignedData.Text, txtKey.Text, txtSignature.Text);
         }
         this.Close();
     }
 }