function trim(cad) {
	if(cad)
		return cad.replace(/^\s+|\s+$/g,"");
	else
		return "";
}

function o(cad) {
	return document.getElementById(cad);
}        

function left(str, n){
	if (n <= 0)
	    return "";
	else if (n > String(str).length)
	    return str;
	else
	    return String(str).substring(0,n);
}

function right(str, n){
    if (n <= 0)
       return "";
    else if (n > String(str).length)
       return str;
    else {
       var iLen = String(str).length;
       return String(str).substring(iLen, iLen - n);
    }
}

function refrescapadre()
{
	if (window.opener && !window.opener.closed)
		window.opener.location.reload();
}


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, dtCh, minYear, maxYear){
	
	if (dtCh==null)
		dtCh="/";
		
	if (minYear==null)
		minYear=1900;
		
	if (maxYear==null)
		maxYear=2500;
	
	
	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, 10);
	day=parseInt(strDay, 10);
	year=parseInt(strYr, 10);
	if (pos1==-1 || pos2==-1){
		return false;
	}
	if (strMonth.length<1 || month<1 || month>12){
		return false;
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		return false;
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		return false;
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		return false;
	}
	return true;
}

/////////// PRELODEAR Y CAMBIAR IMAGENES by gaby //////////////////

function preload() 
{
	var imagenes=new Array();
	a=preload.arguments;
	for(i=0; i<a.length; i++)
	{
    	if (a[i].indexOf("#")!=0)
    	{
    		imagenes[i]=new Image;
    		imagenes[i].src=a[i];
    	}
    }
}


function cambiarimg(img, newimg)
{
	img.src=newimg;
}