// Compara dates(data1,data2)
// retorna 
//  	-1 si data1 > data2
//		0  si data1 = data2
//		1 si data1 < data2
function compara_dates(data1,data2)
{

	var pos,pos2,d1,m1,a1,d2,m2,a2,error;
	
	pos = data1.indexOf('/')
	pos2 = data1.indexOf('/',pos+1);
	d1  = Number(data1.substr(0,pos));
	m1  = Number(data1.substr(pos+1,pos2-(pos+1)));
	a1  = Number(data1.substr(pos2+1,data1.length-(pos2+1)));

	pos = data2.indexOf('/')
	pos2 = data2.indexOf('/',pos+1);
	d2  = Number(data2.substr(0,pos));
	m2  = Number(data2.substr(pos+1,pos2-(pos+1)));
	a2  = Number(data2.substr(pos2+1,data2.length-(pos2+1)));
	
	
	error=false;
	
	if (a1>a2)
	{
		return -1;
	}
	
	if (a1<a2)
	{
		return 1;
	}

	if(m1>m2)
	{
		return -1;
						
	}

	if(m1<m2)
	{
		return 1;
						
	}
			
	if (d1>d2) 
	{
		return -1;
	}

	if (d1<d2) 
	{
		return 1;
		
	}
	
	return 0;

}

function data_correcte(data)
{
	var reg_data = /[0-9]{1,2}\/[0-9]{1,2}\/[0-9]{4}/,error=true,pos,pos2,pos3;
//	var reg_data = /[0-9]{1,2}[/-]{1}[0-9]{1,2}[/-]{1}[0-9]{4}/,error=true,pos,pos2,pos3;

	if (reg_data.test(data)) 
	{	
		pos = data.indexOf("/")
		pos2 = data.indexOf("/",pos+1);
		dia  = Number(data.substr(0,pos));
		mes  = Number(data.substr(pos+1,pos2-(pos+1)));
		an   = Number(data.substr(pos2+1,data.length-(pos2+1)));
		if (an>=1700)
		{
			if ((mes>=1) && (mes<=12))
			{
				switch (mes)
				{
					case 1:
					case 3:
					case 5:
					case 7:
					case 8:
					case 10:
					case 12:
						if ((dia<=31) && (dia>=1))
						{
							error= false;			
						}
						break;
						
					case 4:
					case 6:
					case 9:
					case 11:
						if ((dia<=30) && (dia>=1))
						{
							error= false;			
						}
						break;

					case 2:
						if ((an % 4)==0)
						{
							if (dia<=29) error= false;						
						}
						else
						{
							if (dia<=28) error= false;
						}
						break;						
				}		
			}				
		}
	}
	return (!error);
}



// Retorna l'ultim dia del més
function ultim_dia_mes(mes,an)
{

	var 
		dia;
		
	if ((mes>=1) && (mes<=12))
	{
		switch (mes)
		{
			case 1:
			case 3:
			case 5:
			case 7:
			case 8:
			case 10:
			case 12:
				dia = 31;
				break;
						
			case 4:
			case 6:
			case 9:
			case 11:
				dia = 30;
				break;

			case 2:
				if ((an % 4)==0)
				{
					dia = 29;
				}
				else
				{
					dia = 28;
				}
					
				break;						
		}		
	}				
	else
		dia = -1;
		
	return dia;
	
}

// suma n dies a la data actual dd/mm/yyyy
function suma_n_dies(data,n)
{
	var i,data2;
	
	data2=data;
	
	for(i=0;i<n;i++)
		data2=suma_un_dia(data2);

	return data2;
}

// suma un dia a la data actual dd/mm/yyyy
function suma_un_dia(data)
{

	var pos,pos2,dia,mes,an,tmp='';
	
	pos = data.indexOf("/");
	pos2 = data.indexOf("/",pos+1);
	dia  = Number(data.substr(0,pos));
	mes  = Number(data.substr(pos+1,pos2-(pos+1)));
	an   = Number(data.substr(pos2+1,data.length-(pos2+1)));
	
	dia++;
	
	if (dia>ultim_dia_mes(mes,an))
	{
		dia = 1;
		mes++;
		if (mes>12)
		{
			mes=1;
			an++;
		}
	}
	tmp = tmp.concat(String(dia),'/',String(mes),'/',String(an));	
	return tmp
}