var contmes=0
function actualizaFecha(cmbdiai,cmbmesi,cmbanioi,cmbdiaf,cmbmesf,cmbaniof){
	for(i = cmbdiai.length - 1; i >= 0; i--){
		if(navigator.appName == "Netscape"){
			cmbdiai.options[i] = null;
			cmbdiaf.options[i] = null;
		}
		else{
			cmbdiai.remove(i);
			cmbdiaf.remove(i);
		}
	}
	for(i=1;i<=31;i++){
		if(i<10){
			cmbdiai.options[cmbdiai.length]=new Option("0"+i,"0"+i);
			cmbdiaf.options[cmbdiaf.length]=new Option("0"+i,"0"+i);
		}
		else{
			cmbdiai.options[cmbdiai.length]=new Option(i,i);
			cmbdiaf.options[cmbdiaf.length]=new Option(i,i);
		}
	}
	dia = actual.getDate()-1;
	mes = actual.getMonth();
	anio = actual.getYear()-1;
	cmbdiai.selectedIndex=dia;

	if((dia==31)||(dia==30))
		cmbdiaf.selectedIndex=0;
	else
		cmbdiaf.selectedIndex=dia+1

	actualizaMes(cmbdiai,cmbmesi)
	actualizaMes(cmbdiaf,cmbmesf)

	actualizaAnio(cmbdiai,cmbmesi,cmbanioi)
	actualizaAnio(cmbdiaf,cmbmesf,cmbaniof)

}

function actualizaMes(combo1,combo2){
	dia=combo1.options[combo1.selectedIndex].value;
	for(i = combo2.length - 1; i >=0; i--){
		if(navigator.appName == 'Netscape')
			combo2.options[i] = null;
		else
			combo2.remove(i);
	}
	if (dia==31){
		combo2.options[combo2.length]=new Option("Ene","01");
		combo2.options[combo2.length]=new Option("Mar","03");
		combo2.options[combo2.length]=new Option("May","05");
		combo2.options[combo2.length]=new Option("Jul","07");
		combo2.options[combo2.length]=new Option("Ago","08");
		combo2.options[combo2.length]=new Option("Oct","10");
		combo2.options[combo2.length]=new Option("Dic","12");
	}
	if (dia==30) {
		for(i=1;i<=12;i++){
			if(i!=2)
				if(i==1) combo2.options[combo2.length]=new Option("Ene","01");
				if(i==3) combo2.options[combo2.length]=new Option("Mar","03");
				if(i==4) combo2.options[combo2.length]=new Option("Abr","04");
				if(i==5) combo2.options[combo2.length]=new Option("May","05");
				if(i==6) combo2.options[combo2.length]=new Option("Jun","06");
				if(i==7) combo2.options[combo2.length]=new Option("Jul","07");
				if(i==8) combo2.options[combo2.length]=new Option("Ago","08");
				if(i==9) combo2.options[combo2.length]=new Option("Sep","09");
				if(i==10) combo2.options[combo2.length]=new Option("Oct","10");
				if(i==11) combo2.options[combo2.length]=new Option("Nov","11");
				if(i==12) combo2.options[combo2.length]=new Option("Dic","12");
		}
	}
	if (dia<30) {
		for(i=1;i<=12;i++){
				if(i==1) combo2.options[combo2.length]=new Option("Ene","01");
				if(i==2) combo2.options[combo2.length]=new Option("Feb","02");
				if(i==3) combo2.options[combo2.length]=new Option("Mar","03");
				if(i==4) combo2.options[combo2.length]=new Option("Abr","04");
				if(i==5) combo2.options[combo2.length]=new Option("May","05");
				if(i==6) combo2.options[combo2.length]=new Option("Jun","06");
				if(i==7) combo2.options[combo2.length]=new Option("Jul","07");
				if(i==8) combo2.options[combo2.length]=new Option("Ago","08");
				if(i==9) combo2.options[combo2.length]=new Option("Sep","09");
				if(i==10) combo2.options[combo2.length]=new Option("Oct","10");
				if(i==11) combo2.options[combo2.length]=new Option("Nov","11");
				if(i==12) combo2.options[combo2.length]=new Option("Dic","12");
		}
	}
	if(mes.length==1)
		mes = "0"+(actual.getMonth()+1);
	else
		mes = (actual.getMonth()+1);
	for(i=0;i<combo2.length;i++){
		if (combo2.options[i].value==mes)
			if(contmes<=50)
				combo2.selectedIndex=i;
			else
				combo2.selectedIndex=0
	}
	contmes=contmes+1
}

function actualizaAnio(combo1,combo2,combo3){
	dia=combo1.options[combo1.selectedIndex].value;
	mes=combo2.options[combo2.selectedIndex].value;
	for(i = combo3.length - 1; i >=0; i--){
		if(navigator.appName == 'Netscape')
			combo3.options[i] = null;
		else
			combo3.remove(i);
	}
	if ((dia==29)&&(mes==02)){
		for(i=1;i<=5;i++){
			anio=2000+(i*4)
			combo3.options[combo3.length]=new Option(anio,anio);
		}
	}
	else{
		if ((dia==30)&&(mes==02)){
			combo3.options[combo3.length]=new Option("xxxx","na");
		}
		else{
			for(i=0;i<=20;i++){
				anio=2000+i
				combo3.options[combo3.length]=new Option(anio,anio);
			}
		}
	}
	anio = actual.getYear();
	for(i=0;i<combo3.length;i++){
		if (combo3.options[i].text==anio){
			combo3.selectedIndex=i
		}
	}
}