var fDesc=new Array(); fDesc[0] = "With PINTAR VirtuaLab Sound, test out the phenomenon of sound – Doppler Effect, Saw Tooth wave, Square wave and Triangle wave. Adjust the frequency, amplitude, initial phase, wave type or speed, tension and length. Users can change the properties and track the result.Listen to sounds as they run and observe the wave reflection."; function tShowHide(id, show) { var s = document.getElementById("desc"); if ((s.innerHTML.length<=212 || show==1) && show!=2) { s.innerHTML = fDesc[id]; if (document.getElementById('m1')) document.getElementById('m1').style.display='none'; if (document.getElementById('m2')) document.getElementById('m2').style.display='none'; if (document.getElementById('more_txt')) document.getElementById('more_txt').style.display='inline'; } else { s.innerHTML = ''; } }