"Greek Astronomy", "The Birth of Modern Astronomy", "Introduction to Orbits and Gravity", "The Laws of Planetary Motion", "Newton’s Great Synthesis", "Newton’s Universal Law of Gravitation", "Orbits in the Solar System", "Motions of Satellites and Spacecraft", "Gravity with More Than Two Bodies", "Earth and Sky", "The Seasons", "The Seasons at Different Latitudes", "Keeping Time", "The Calendar", "Phases and Motions of the Moon", "The Moon’s Revolution and Rotation", "Ocean Tides and the Moon", "Eclipses of the Sun and Moon", "Introduction to Radiation and Spectra", "The Behavior of Light", "The Electromagnetic Spectrum", "Spectroscopy in Astronomy", "Types of Spectra", "The Structure of the Atom", "Formation of Spectral Lines", "The Doppler Effect", "Introduction to Astronomical Instruments", "Telescopes", "How Telescopes Work", "Satellite Orbits and Energy" stringArrayList.add("Greek Astronomy"); stringArrayList.add("The Birth of Modern Astronomy"); stringArrayList.add("Introduction to Orbits and Gravity"); stringArrayList.add("The Laws of Planetary Motion"); stringArrayList.add("Newton’s Great Synthesis"); stringArrayList.add("Newton’s Universal Law of Gravitation"); stringArrayList.add("Orbits in the Solar System"); stringArrayList.add("Motions of Satellites and Spacecraft"); stringArrayList.add("Gravity with More Than Two Bodies"); stringArrayList.add("Earth and Sky"); stringArrayList.add("The Seasons"); stringArrayList.add("The Seasons at Different Latitudes"); stringArrayList.add("Keeping Time"); stringArrayList.add("The Calendar"); stringArrayList.add("Phases and Motions of the Moon"); stringArrayList.add("The Moon’s Revolution and Rotation"); stringArrayList.add("Ocean Tides and the Moon"); stringArrayList.add("Eclipses of the Sun and Moon"); stringArrayList.add("Introduction to Radiation and Spectra"); stringArrayList.add("The Behavior of Light"); stringArrayList.add("The Electromagnetic Spectrum"); stringArrayList.add("Spectroscopy in Astronomy"); stringArrayList.add("Types of Spectra"); stringArrayList.add("The Structure of the Atom"); stringArrayList.add("Formation of Spectral Lines"); stringArrayList.add("The Doppler Effect"); stringArrayList.add("Introduction to Astronomical Instruments"); stringArrayList.add("Telescopes"); stringArrayList.add("How Telescopes Work"); stringArrayList.add("Satellite Orbits and Energy"); if (selected.equals("Greek Astronomy")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/1.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Birth of Modern Astronomy")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/2.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Introduction to Orbits and Gravity")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/3.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Laws of Planetary Motion")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/4.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Newton’s Great Synthesis")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/5.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Newton’s Universal Law of Gravitation")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/6.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Orbits in the Solar System")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/7.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Motions of Satellites and Spacecraft")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/8.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Gravity with More Than Two Bodies")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/9.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Earth and Sky")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/10.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Seasons")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/11.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Seasons at Different Latitudes")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/12.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Keeping Time")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/13.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Calendar")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/14.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Phases and Motions of the Moon")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/15.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Moon’s Revolution and Rotation")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/16.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Ocean Tides and the Moon")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/17.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Eclipses of the Sun and Moon")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/18.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Introduction to Radiation and Spectra")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/19.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Behavior of Light")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/20.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Electromagnetic Spectrum")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/21.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Spectroscopy in Astronomy")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/22.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Types of Spectra")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/23.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Structure of the Atom")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/24.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Formation of Spectral Lines")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/25.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("The Doppler Effect")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/26.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Introduction to Astronomical Instruments")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/27.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Telescopes")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/28.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("How Telescopes Work")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/29.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); } if (selected.equals("Satellite Orbits and Energy")) { Intent i = new Intent(MainActivity.this, DetailActivity.class); i.putExtra("id", position); i.putExtra("url" , "file:///android_asset/30.htm" ); i.putExtra( "value", adapter.getItem(position)); startActivity(i); }