function inicia(){
	//for (k=1; k<10; k++){
	
	//nomdecapa = "capa"+k
	//punt1 = eval(nomdecapa+".style");
	
	if (nocapes = false) return false;
	punt1 = capa1.style;
	punt1.xpos=parseInt(punt1.left);
	punt1.ypos=parseInt(punt1.top);
	punt1.active = true;
	punt2 = capa2.style;
	punt2.xpos=parseInt(punt2.left);
	punt2.ypos=parseInt(punt2.top);
	punt3 = capa3.style;
	punt3.xpos=parseInt(punt3.left);
	punt3.ypos=parseInt(punt3.top);
	punt4 = capa4.style;
	punt4.xpos=parseInt(punt4.left);
	punt4.ypos=parseInt(punt4.top);
	punt5 = capa5.style;
	punt5.xpos=parseInt(punt5.left);
	punt5.ypos=parseInt(punt5.top);
	punt6 = capa6.style;
	punt6.xpos=parseInt(punt6.left);
	punt6.ypos=parseInt(punt6.top);
	punt7 = capa7.style;
	punt7.xpos=parseInt(punt7.left);
	punt7.ypos=parseInt(punt7.top);
	punt8 = capa8.style;
	punt8.xpos=parseInt(punt8.left);
	punt8.ypos=parseInt(punt8.top);
	
}

nocapes=true;
var ample;

function creacapes(){
var j=0,posx,lon_corda;ample
t=0;
if (document.all.capa1 == null) { 
	ample = document.forms[0].amplitud.value;
	grav = document.forms[0].gravetat.value
	lon_corda = document.forms[0].long_corda.value;
	if (!lon_corda) lcorda = 100;
	else lcorda = lon_corda;
		//for (j = 0; j <9; j++){
		//posx = 150;
		periode=2*Math.PI*Math.sqrt(lcorda/100/grav);
		//alert(periode);
		creapunt(400,50+lcorda,1);
		creacorda(400,50+lcorda/8,2);
		creacorda(400,50+2*lcorda/8,3);
		creacorda(400,50+3*lcorda/8,4);
		creacorda(400,50+4*lcorda/8,5);
		creacorda(400,50+5*lcorda/8,6);
		creacorda(400,50+6*lcorda/8,7);
		creacorda(400,50+7*lcorda/8,8);
		//}
	}
	else {nocapes = false; t=0; punt1.active = false; return false;}
	
}
var n=0;
function moviment(){
	if (nocapes = false) return false;
	if (punt1.active){
		temps=10;
		t = ms/1000;
		if (n>0) document.crono.nombre.value = n-1;
		if (t>n*periode) n++;
		punt1.xpos = 398+ample*(Math.sin(2*Math.PI*t/periode+Math.PI/2));
		pos1x = parseInt(punt1.xpos);
		punt1.ypos = 50+(lcorda-1)+Math.sqrt(Math.pow(lcorda,2)-Math.pow(pos1x-398,2));
		pos1y = parseInt(punt1.ypos);
		
		punt1.left = pos1x;
		punt1.top = pos1y;
		angle=Math.atan((pos1x-398)/(pos1y-50-lcorda));
		poscorda1x=400+lcorda/8*Math.sin(angle);
		poscorda1y=50+lcorda/8+lcorda/8*Math.cos(angle);
		punt2.left = parseInt(poscorda1x);
		punt2.top = parseInt(poscorda1y);
		poscorda2x=400+2*lcorda/8*Math.sin(angle);
		poscorda2y=50+2*lcorda/8+2*lcorda/8*Math.cos(angle);
		punt3.left = parseInt(poscorda2x);
		punt3.top = parseInt(poscorda2y);
		poscorda3x=400+3*lcorda/8*Math.sin(angle);
		poscorda3y=50+3*lcorda/8+3*lcorda/8*Math.cos(angle);
		punt4.left = parseInt(poscorda3x);
		punt4.top = parseInt(poscorda3y);
		poscorda4x=400+4*lcorda/8*Math.sin(angle);
		poscorda4y=50+4*lcorda/8+4*lcorda/8*Math.cos(angle);
		punt5.left = parseInt(poscorda4x);
		punt5.top = parseInt(poscorda4y);
		poscorda5x=400+5*lcorda/8*Math.sin(angle);
		poscorda5y=50+5*lcorda/8+5*lcorda/8*Math.cos(angle);
		punt6.left = parseInt(poscorda5x);
		punt6.top = parseInt(poscorda5y);
		poscorda6x=400+6*lcorda/8*Math.sin(angle);
		poscorda6y=50+6*lcorda/8+6*lcorda/8*Math.cos(angle);
		punt7.left = parseInt(poscorda6x);
		punt7.top = parseInt(poscorda6y);
		poscorda7x=400+7*lcorda/8*Math.sin(angle);
		poscorda7y=50+7*lcorda/8+7*lcorda/8*Math.cos(angle);
		punt8.left = parseInt(poscorda7x);
		punt8.top = parseInt(poscorda7y);
		
		//t +=0.01;
		//if (t>15) punt1.active = false;
		
		setTimeout("moviment()",temps);
	}
}

function creapunt(x,y,n) {

	var nomcapa ="capa"+n;
	var cadena='<div id="'+nomcapa+'" style="visibility: visible; z-index: 10; background-color: #FFFFFF; position: absolute; left:'+x+'px; top:'+y+'px; border: 0"><img src="bolla.gif" width="5" height="5"></div>';
	document.body.insertAdjacentHTML('beforeEnd',cadena);
								
}

function creacorda(x,y,n) {

	var nomcapa ="capa"+n;
	var cadena='<div id="'+nomcapa+'" style="visibility: visible; z-index: 10; background-color: #FFFFFF; position: absolute; left:'+x+'px; top:'+y+'px; border: 0"><img src="pixelnegre.gif" width="2" height="2"></div>';
	document.body.insertAdjacentHTML('beforeEnd',cadena);
								
}

var ms = 0;
var estat = 0;
var comptador=0;
function inicrono() {
  if (estat == 0) {
   estat = 1;
   tinicial = new Date();
   tinicial.setTime(tinicial.getTime() - ms);
  } else {
   punt1.active = false;
   estat = 0;
   tactual = new Date();
   ms = tactual.getTime() - tinicial.getTime();
   document.form1.temps.value = ms/1000;
   }
}

function swreset() {
   estat = 0;
   ms = 0;
   document.crono.nombre.value = ms;
}

function display() {
   setTimeout("display();", 50);

   if (estat == 1)  {
   tactual = new Date();
   ms = tactual.getTime() - tinicial.getTime();
   document.form1.temps.value = ms/1000;
}

   }