private void SoCau_text_TextChanged(object sender, EventArgs e)
 {
     if (comboBox1.Text == "PART I")
     {
         if ((P1_SoCau > 0) && (P1_SoCau < 51))
         {
             LastCheckDisplay();
             PicAddr = PathText.Text + "PartI_Pic" + P1_SoCau.ToString() + ".JPG";
             pictureBox1.ImageLocation = PicAddr;
             SoundAddr = PathSound.Text + "PartI_Sound" + P1_SoCau.ToString() + ".wav";
             Sound     = new SoundPlayer(SoundAddr);
             Sound.Play();
         }
         else
         {
             MessageBox.Show("Numbers are out of range (1 - 50)", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
         }
     }
     else
     {
         if ((P2_SoCau > 0) && (P2_SoCau < 101))
         {
             LastCheckDisplay();
             PicAddr = PathText.Text + "PartII_Pic" + P2_SoCau.ToString() + ".JPG";
             pictureBox1.ImageLocation = PicAddr;
             SoundAddr = PathSound.Text + "PartII_Sound" + P2_SoCau.ToString() + ".wav";
             Sound     = new SoundPlayer(SoundAddr);
             Sound.Play();
         }
         else
         {
             MessageBox.Show("Numbers are out of range (1 - 100)", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
         }
     }
 }
 private void Previous_Click(object sender, EventArgs e)
 {
     if (comboBox1.Text == "PART I")
     {
         if (P1_SoCau > 1)
         {
             P1_SoCau--;
             SoCau_text.Text = P1_SoCau.ToString();
         }
         else
         {
             MessageBox.Show("Numbers are out of range (1 - 50)", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
         }
     }
     else
     {
         if (P2_SoCau > 1)
         {
             P2_SoCau--;
             SoCau_text.Text = P2_SoCau.ToString();
         }
         else
         {
             MessageBox.Show("Numbers are out of range (1 - 100)", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
         }
     }
 }