Inserting AVI Video into VideoSourcePlayer in C#

private bool CheckValidity(string strName)
        {
            //show error if user specified invalid file
            if (strName.EndsWith(".avi") == false)
            {
                MessageBox.Show("File name must end with .avi", "Invaild File Type", MessageBoxButtons.OK, MessageBoxIcon.Error);
                MessageBox.Show("Fill in the empty box");
                return false;//to indicate invalid file type
            }

            //change status of Buttons if file name is valid
            else
            {
                btnOpenFile.Enabled = false;
                btnEnter.Enabled = true;

                return true;//to indicate text file specified
            }
        }//end method CheckValidity


        private void btnLoadImage_Click(object sender, EventArgs e)
        {
            if (objOpenFileDialog.ShowDialog() == DialogResult.OK)
            {
                // create video source
                AVIFileVideoSource fileSource = new AVIFileVideoSource(objOpenFileDialog.FileName);

                OpenVideoSource(fileSource);


            }

        }