var fDesc=new Array(); fDesc[0] = "Forces and Motion: Basics is a simulation that deals with the topics of force, motion, friction, speed, and Newton's first law.. It allows students to explore the forces at work in a tug of war or pushing a refrigerator, crate, or person; create an applied force and see how it makes objects move; change friction and see how it affects the motion of objects."; 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 = ''; } }