function validaData( input ){
	
	var data 	= document.getElementById( input );

	var dia 	= data.value.substr( 0, 2 );
	var mes 	= data.value.substr( 3, 2 );
	var ano 	= data.value.substr( 6,4 );

	if( data.value == '' ){
		alert( "A data não pode ser vazia" );
	}
	else if( !isDate( dia, mes, ano ) || ano < 1900 ){
		alert( "Data inválida!" );
	}
	
}

// Verifica se a data apresentada ou no uma data válida
function isDate(day, month, year) {
	//IsDate(29, 2, 2005)
	//IsDate(29, 2, 2004)
	var date = new Date();
	var blnRet = false;
	var blnDay;
	var blnMonth;
	var blnYear;

	date.setFullYear(year, month -1, day);

	blnDay   = (date.getDate()      == day);
	blnMonth = (date.getMonth()     == month -1);
	blnYear  = (date.getFullYear()  == year);

	if (blnDay && blnMonth && blnYear)
	blnRet = true;

	return blnRet;
	
}

window.addEvent( "domready", function(){
	
	var jcalendar = $$( ".calendar" );
	
	if( jcalendar.length > 0 ){

		$each( jcalendar, function(jc){

			var inputCalendar = jc.id.substr( 0, new Number( jc.id.length ) - 4 );
			
			var arrNum = new Array( 8, 9, 13, 17, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 116 );
			
			//Adding the click event to show Joomla! calendar
			$(jc.id).addEvent( "click", function(){
				showCalendar( inputCalendar, "%d/%m/%Y" );
			});

			//Adding the maxlength to the input that will accept the calendar value
			$( inputCalendar ).set( "maxlength", "10" );
			
			//Adding the events in case of the user write the date value
			$( inputCalendar ).addEvent( "keydown", function(e){

				var inArray = false;
				
				for( var i = 0; i < arrNum.length; i++ ){		
					if( e.code == arrNum[i] ){
						inArray = true;
						break;
					}
				}

				if( !inArray ){
					return false;
				}
				
				if( ( this.value.length == 2 || this.value.length == 5 ) && e.code != 8 ){
					this.value = this.value + "/";
				}
				
			});
			
		});

	}
	
});