var dtCh= "-";
var minYear=1900;
var maxYear=2100;

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}


function daysInFebruary (year){
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function addDay(dtStr){
	
	var fecha = new Date();
	fecha = toDate(dtStr);
	fecha = add_days(fecha,1);
	var dia = fecha.getDate();
	var mes = fecha.getMonth()+1;
	var anno = fecha.getFullYear();
	return dia+dtCh+mes+dtCh+anno;
	}

function add_days(date,delta) {

  var result = new Date();
  result.setTime(date.getTime() + delta*(24 * 60 * 60 *1000) );
  
  if (result.getDate() == date.getDate()) {
    result.setTime( result.getTime() + (delta > 0 ? 1 : -1 ) *60 * 60 * 1000);
  }

  result.setHours( date.getHours());

  return result;
}

function toDate(dtStr){
	var daysInMonth = DaysArray(12);
	var pos1=dtStr.indexOf(dtCh);
	var pos2=dtStr.indexOf(dtCh,pos1+1);
	var strDay=dtStr.substring(0,pos1);
	var strMonth=dtStr.substring(pos1+1,pos2);
	var strYear=dtStr.substring(pos2+1);
	return new Date(strYear,strMonth-1,strDay);
}
function normalizaDate(dtStr){
//	alert(dtStr);
	var daysInMonth = DaysArray(12);
	var pos1=dtStr.indexOf(dtCh);
	var pos2=dtStr.indexOf(dtCh,pos1+1);
	var strDay=dtStr.substring(0,pos1);
	var strMonth=dtStr.substring(pos1+1,pos2);
	var strYear=dtStr.substring(pos2+1);
	if (strDay.length==1) strDay = "0"+ strDay;
	if (strMonth.length==1) strMonth = "0"+ strMonth;
	return strDay+dtCh+strMonth+dtCh+strYear; 
}
	
function isDate(dtStr){
	var daysInMonth = DaysArray(12)
	var pos1=dtStr.indexOf(dtCh)
	var pos2=dtStr.indexOf(dtCh,pos1+1)
	var strDay=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strYear=dtStr.substring(pos2+1)
	strYr=strYear
//	alert(dtStr);
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
	}
	month=parseInt(strMonth)
	day=parseInt(strDay)
	year=parseInt(strYr)
	if (pos1==-1 || pos2==-1){
		alert(msgerror_fechas[0])
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		alert(msgerror_fechas[1])
		return false
	}

	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert(msgerror_fechas[2])
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert("El formato anual debe estar entre "+minYear+" y "+maxYear)
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert("Inserte una fecha correcta")
		return false
	}
return true
}