// whitespace characters
var whitespace = " \t\n\r";


//Verifica se una stringa contiene un numero

function numCheck(argvalue) {

  if (argvalue.length == 0)
    return false;

  for (var n = 0; n < argvalue.length; n++)
    if (argvalue.substring(n, n+1) < "0" || argvalue.substring(n, n+1) > "9")
      return false;

  return true;

}

function voteCheck(argvalue) {

  if (argvalue.length == 0)
    return false;

  for (var n = 0; n < argvalue.length; n++)
    if ((argvalue.substring(n, n+1) < "0" || argvalue.substring(n, n+1) > "9") && argvalue.substring(n, n+1) != "/")
      return false;

  return true;

}


function dataCheck(argvalue) {
   
	if (argvalue.length != 10) { return false;}
	if (argvalue.substring(0, 1) < "0" || argvalue.substring(0, 1) > "9") { return false;}
	if (argvalue.substring(1, 2) < "0" || argvalue.substring(1, 2) > "9") { return false;}
	if (argvalue.substring(2, 3) != "/") {alert("err1/"); return false;}
	if (argvalue.substring(3, 4) < "0" || argvalue.substring(3, 4) > "9") { return false;}
	if (argvalue.substring(4, 5) < "0" || argvalue.substring(4, 5) > "9") { return false;}
	if (argvalue.substring(5, 6) != "/") {alert("err2/"); return false;}
	if (argvalue.substring(6, 7) < "0" || argvalue.substring(6, 7) > "9") { return false;}
	if (argvalue.substring(7, 8) < "0" || argvalue.substring(7, 8) > "9") { return false;}
	if (argvalue.substring(8, 9) < "0" || argvalue.substring(8, 9) > "9") { return false;}
	if (argvalue.substring(9, 10) < "0" || argvalue.substring(9, 10) > "9") { return false;}
  var gg = parseInt(argvalue.substring(0,2));
  var mm = parseInt(argvalue.substring(3,4));
  var aaaa = parseInt(argvalue.substring(6,10));
  if ((gg<1) && (gg>31)){return false;}
  if ((mm<1) && (mm>12)){return false;}
  if ((aaaa<1900) || (aaaa>2001)) {return false;}
  
  return true;
  

}


// Returns true if string s is empty or 
// whitespace characters only.

function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}

// Check whether string s is empty.

function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}

// Returns true if string s is empty or 
// whitespace characters only.

function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}


//Verifica un indirizzo di e-mail

function isEmail (s)
{    
   
    // is s whitespace?
    if (isWhitespace(s)) return false;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;

    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;

    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }

    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    
    return true;

}

//Verifica una Stringa

function isStringa(argvalue) {
  var onechar = "";

  for (var n = 0; n < argvalue.length; n++) {
    onechar = argvalue.substring(n, n+1);
    if ((onechar < "A" || onechar > "Z") && (onechar < "a" || onechar > "z") && (onechar!="'")) {
      return false;
    }
  }

  return true;

}

//Verifica una Stringa con spazi

function isStringaSpc(argvalue) {
  var onechar = "";

  for (var n = 0; n < argvalue.length; n++) {
    onechar = argvalue.substring(n, n+1);
    if ((onechar < "A" || onechar > "Z") && (onechar < "a" || onechar > "z") && (onechar!=" ") && (onechar!="'")) {
      return false;
    }
  }

  return true;

}


//Verifica un numero di telefono

function isPhone(argvalue) {
  var onechar = "";

  for (var n = 0; n < argvalue.length; n++) {
    onechar = argvalue.substring(n, n+1);
    if ((onechar < "0" || onechar > "9") && (onechar!=" ") && (onechar!="-") && (onechar!="+") ) {
      return false;
    }
  }
  
  if (argvalue.length<3) return false;
    
  return true;

}