var dtCh= "/";
var dtHr= ":";
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 isDate(dtStr,Msg){
	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
	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){
		if (Msg==1) {alert("El formato de la fecha debe ser : dd/mm/aaaa");}
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		if (Msg==1) {alert("El mes introducido es incorrecto");}
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		if (Msg==1) {alert("El día introducido es incorrecto");}
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		if (Msg==1) {alert("Introduzca un año entre "+minYear+" y "+maxYear);}
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		if (Msg==1) {alert("La fecha introducida no es correcta");}
		return false
	}
return true
}

function isHour(dtStr,Msg){
	var pos1=dtStr.indexOf(dtHr)
	var strHora=dtStr.substring(0,pos1)
	var strMinutos=dtStr.substring(pos1+1)

	if (strHora.charAt(0)=="0" && strHora.length>1) strHora=strHora.substring(1)
	if (strMinutos.charAt(0)=="0" && strMinutos.length>1) strMinutos=strMinutos.substring(1)

	Hora=parseInt(strHora)
	Minutos=parseInt(strMinutos)

	if (pos1==-1 ){
		if (Msg==1) {alert("El formato de la hora debe ser : hh:mm");}
		return false
	}
	if (strHora.length<1 || Hora<0 || Hora>24){
		if (Msg==1) {alert("La hora introducida es incorrecta");}
		return false
	}
	if (strMinutos.length<1 || Minutos<0 || Minutos>59){
		if (Msg==1) {alert("Los minutos son incorrectos");}
		return false
	}
return true
}

//recibe una fecha en formato dd/mm/aaaa y le suma los días que vienen en el parámetro
function SumarFecha(Fecha, Dias){
	var dateArr = Fecha; 
	var date1 = new Date(); 
	// assume entered in dd/mm/yyyy format - no validation check. 
	date1.setFullYear(dateArr[2],dateArr[1]-1,dateArr[0]); 
	date1.setDate(date1.getDate()+Dias); 
	
// add leading zero if the length equals 1 if(month<10) month = "0"+month; if(day<10) day = "0"+day;
	
	return date1.getDate() + "/" + (date1.getMonth()+1) + "/" + date1.getFullYear();
}