var fDesc=new Array();
fDesc[0] = "Lurch is a program for teaching and learning mathematical proofs. It supports full mathematical typesetting of math expressions in either TeX or calculator notation; it is built on OpenMath for unambiguous semantics. Users can add new math topics to this program.";

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 = '';
	}
}