function seleccionaTodos(){
	var marcados=true;
	for (i=0;i<document.form.elements.length;i++){
		if (document.form.elements[i].name.indexOf("chk")==0){
			if (document.form.elements[i].checked==false) marcados=false;
		}
	}
	if (marcados==false){
		for (i=0;i<document.form.elements.length;i++){
			if (document.form.elements[i].name.indexOf("chk")==0){
				document.form.elements[i].checked=true;
			}
		}
	}else{
		for (i=0;i<document.form.elements.length;i++){
			if (document.form.elements[i].name.indexOf("chk")==0){
				document.form.elements[i].checked=false;
			}
		}
	}
}

function changeSelect(id){
	if(document.getElementById(id).selectedIndex < 2)
		document.getElementById(id).selectedIndex = 0;
}

function check_email(e){
	ok = "1234567890qwertyuiop[]asdfghjklzxcvbnm.@-_QWERTYUIOPASDFGHJKLZXCVBNM";
	for(i=0; i < e.length ;i++){
		if(ok.indexOf(e.charAt(i))<0){ 
			return (false);
		}	
	} 
	if (document.images){
		re = /(@.*@)|(\.\.)|(^\.)|(^@)|(@$)|(\.$)|(@\.)/;
		re_two = /^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;
		if (!e.match(re) && e.match(re_two)){
			return (-1);		
		} 
	}
}

function isUrl(s) {
    var regexp = /(ftp|http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/
    return regexp.test(s);
}

function ismaxlength(obj){
	var mlength=obj.getAttribute? parseInt(obj.getAttribute("maxlength")) : ""
	if (obj.getAttribute && obj.value.length>mlength)
	obj.value=obj.value.substring(0,mlength)
}

function checkdate(pObject){
	if (pObject.value == ""){return false;}

	var date = new Date();
	var day = date.getDate();
	var month = date.getMonth()+1;
	var year = date.getFullYear();

	if (day.toString().length==1){day = "0"+day;}
	if (month.toString().length==1){month = "0"+month;}

	cDate = pObject.value.split("/");

	if(cDate[2]){
		var cDay = cDate[0];
		var cMonth = cDate[1];
		var cYear = cDate[2];
		
		if (cDay.length==0){cDay = day}
		if (cDay.length==1){cDay = "0"+cDay}
		if (cMonth.length==0){cMonth = month}
		if (cMonth.length==1){cMonth = "0"+cMonth}
		if (cYear.length==0){cYear = year}
		if (cYear.length==1){cYear = "200"+cYear}
		if (cYear.length==2){cYear = "20"+cYear}
		if (cYear.length==3){cYear = "200"+cYear.substr(2,1)}
	
		cDay = cDay.toString().substr(0,2);
		cMonth = cMonth.toString().substr(0,2);
		cYear = cYear.toString().substr(0,4);
	
		if (cDay<1 || cDay>31 || cMonth<1 || cMonth>12 || cYear<2000 || cYear>2100){
			alert("Formato de fecha non válido!")
			pObject.focus();
			return false;
		}else
			pObject.value = cDay+"/"+cMonth+"/"+cYear;
	}else{
		alert("Formato de fecha no válido! Formato: dd/mm/aaaa")
		pObject.focus();
		return false;
	}
	return true;
}