function main()
{
	var m=document.getElementById("month").selectedIndex+1;
	var d=eval(document.getElementById("day").value);
	var lg=52.53;
	var lat=29.39;

	var ep=sun(m,d,4,lg)
	var zr=ep[0];
	delta=ep[1];
	ha=loc2hor(108.0,delta,lat)
	var t1=Round(zr-ha,24)
	ep=sun(m,d,t1,lg)
	zr=ep[0];
	delta=ep[1];
	ha=loc2hor(108.0,delta,lat)
	var t1=Round(zr-ha,24)
	document.getElementById("t1").innerHTML=hms(t1);
//
//   t2= Sun rise
//
	ep=sun(m,d,6,lg)
	zr=ep[0];
	delta=ep[1];
	ha=loc2hor(90.833,delta,lat)
	var t2=Round(zr-ha,24)
	ep=sun(m,d,t2,lg)
	zr=ep[0];
	delta=ep[1];
	ha=loc2hor(90.833,delta,lat)
	t2=Round(zr-ha,24)
	document.getElementById("t2").innerHTML=hms(t2);
//	
//	zr=Zohr
//
	ep=sun(m,d,12,lg)
	ep=sun(m,d,ep[0],lg)
	zr=ep[0];
	document.getElementById("zr").innerHTML=hms(zr);
//
//   t2= Sun set
//
	ep=sun(m,d,18,lg)
	zr=ep[0];
	delta=ep[1];
	ha=loc2hor(90.833,delta,lat)
	var t3=Round(zr+ha,24)
	ep=sun(m,d,t3,lg)
	zr=ep[0];
	delta=ep[1];
	ha=loc2hor(90.833,delta,lat)
	t3=Round(zr+ha,24)
	document.getElementById("t3").innerHTML=hms(t3);
//
//   t2= Maghreb
//
	ep=sun(m,d,18.5,lg)
	zr=ep[0];
	delta=ep[1];
	ha=loc2hor(94.3,delta,lat)
	var t4=Round(zr+ha,24)
	ep=sun(m,d,t4,lg)
	zr=ep[0];
	delta=ep[1];
	ha=loc2hor(94.3,delta,lat)
	t4=Round(zr+ha,24)
	document.getElementById("t4").innerHTML=hms(t4);
	
}
function sun(m,d,h,lg)
{
	if(m<7)
		d= 31*(m-1)+d+h/24;
	else
		d=6+30*(m-1)+d+h/24;
	var M=74.2023+0.98560026*d;
	var L=-2.75043+0.98564735*d;
	var lst=8.3162159+0.065709824*Math.floor(d)+1.00273791*24*(d%1)+lg/15;	
	var e=0.0167065;
	var omega=4.85131-0.052954*d;
	var ep=23.4384717+0.00256*cosd(omega);
	var ed=180.0/Math.PI*e;
	var u=M;
	for(var i=1;i<5;i++)
		u=u-(u-ed*sind(u)-M)/(1-e*cosd(u));
	var v=2*atand(tand(u/2)*Math.sqrt((1+e)/(1-e)));
	var theta=L+v-M-0.00569-0.00479*sind(omega);
	var delta=asind(sind(ep)*sind(theta));
	var alpha=180.0/Math.PI*Math.atan2(cosd(ep)*sind(theta),cosd(theta));
	if(alpha>=360)
		alpha-=360;
	var ha=lst-alpha/15;
	var zr=Round(h-ha,24);
	return ([zr,delta])
}

function sind(x){return(Math.sin(Math.PI/180.0*x));}
function cosd(x){return(Math.cos(Math.PI/180.0*x));}
function tand(x){return(Math.tan(Math.PI/180.0*x));}
function atand(x){return(Math.atan(x)*180.0/Math.PI);}
function asind(x){return(Math.asin(x)*180.0/Math.PI);}
function acosd(x){return(Math.acos(x)*180.0/Math.PI);}
function sqrt(x){return(Math.sqrt(x));}
function frac(x){return(x%1);}
function floor(x){return(Math.floor(x));}
function ceil(x){return(Math.ceil(x));}
function loc2hor(z,d,p){
	return(acosd((cosd(z)-sind(d)*sind(p))/cosd(d)/cosd(p))/15);
}
function Round(x,a){
	var tmp=x%a;
	if(tmp<0)
		tmp+=a;
	return(tmp)
}
function hms(x)
{
	x=Math.floor(3600*x);
	h=Math.floor(x/3600);
	mp=x-3600*h;
	m=Math.floor(mp/60);
	s=Math.floor(mp-60*m);
	return(((h<10)? "0" : "")+(h).toString()+":"+((m<10)? "0" : "")+m.toString())
}