function validEmail(field,string) {
    var url = field.value;
    if (url != null && url != "") {
        a = url.lastIndexOf("@");
        b = url.lastIndexOf(".");
        c = url.indexOf(":");
        d = url.indexOf("/");
        e = url.substring(0,a);
        f = e.indexOf("@");
        g = url.substring(a+1,url.length);
        h = g.indexOf("[");
        i = g.indexOf("]");
        j = g.indexOf("<");
        k = g.indexOf(">");
        l = url.substring(a+1,b);
        m = url.substring(b+1,url.length);
        n = url.substring(0,a);
        o = 0;
        if (a > b) {o++};
        if (c != -1) {o++};
        if (d != -1) {o++};
        if (f != -1) {o++};
        if (h != -1) {o++};
        if (i != -1) {o++};
        if (j != -1) {o++};
        if (k != -1) {o++};
        if (l.length < 3) {o++};
        if (m.length < 2) {o++};
        if (n.length < 1) {o++};
        if (o == 0) {
		  return true;
        }
        else {
            alert(string + " does not contain a valid email address!");
			field.focus();
			return false;
        }
    }
	return true;
}

  function num_mand(number,string,flag)
  {
    var numero=number;
    if (eval(flag)==0){
       var checkOK = "0123456789";
    }else{
       var checkOK = "0123456789,";
    }
    if (numero.value.length > 0)
    {
       for (i = 0;  i < numero.value.length;  i++)
       {
          ch = numero.value.charAt(i);
          for (j = 0;  j < checkOK.length;  j++)
            if (ch == checkOK.charAt(j))
            {
   	       break;
            }
            if (j == checkOK.length)
            {
	       alert ("Inert a valid number in '"+string+"'") 
               numero.focus(); 
               return(false);   
            }
       }
    } 
   return(true)
  }

  function dd_mand(field,string)
  {
    if (field.selectedIndex == 0){
        alert ("The field  '" + string+ "' is mandatory ") 
        field.focus();
        return(false);
    }
    return(true)
  }


  function text_mand(field,string)
  {
    if (field.value.length==0)
    {
      alert ("The field  '" + string+ "' is mandatory ") 
      field.focus();
      return(false);           
    }    
    if (field.value.charAt(0)==" "){
      alert ("The field  '" + string+ "' is mandatory ") 
      field.focus();
      return(false);           
    }
    return(true)
  }

  function text_size(field,string,size)
  {
    if (field.value.length>size)
    {
      alert ("The field  '" + string+ "' is too long, maximum is  "+size+" characters ") 
      field.focus();
      return(false);           
    }    
    return(true)
  }
  function ctryear(year,string,flag)
  {
    if (eval(flag) == 0 && (year.value.length == 0))
    {
       return(true)
    }
    else
    {
     if (year.value.length == 0)
     {
       alert ("Insert a valid year in the field  '"+string+"'");
       year.focus();
       return(false);
     }
    }
    if (year.value.length > 0){
      if (eval(year.value)< 1900){
         alert ("Insert a valid year in the field  '"+string+"'")
         year.focus();
         return(false);
      }
    }
    return(true)
  }

  
  function ctrdate(day,month,year,string,flag)
  {

    var giorno=day;
    var mese=month;
    var anno=year;
    var mesi=new Array(12);
    var checkOK = "0123456789";
    mesi.length=12;
    mesi[1]="31";
    mesi[3]="31";
    mesi[4]="30";
    mesi[5]="31";
    mesi[6]="30";
    mesi[7]="31";
    mesi[8]="31";
    mesi[9]="30";
    mesi[10]="31";
    mesi[11]="30";
    mesi[12]="31";

    if (eval(flag) == 0 && (giorno.value.length == 0 && mese.value.length == 0 && anno.value.length == 0))
    {
      return(true);
    }
    else
    {
     if (giorno.value.length == 0 || mese.value.length == 0 || anno.value.length ==0 )
     {
       alert ("Insert a valid date in the field  '"+string+"'");
       giorno.focus();
       return(false);
     }
    }
    if (giorno.value.length > 0)
    {
     for (i = 0;  i < giorno.value.length;  i++)
     {
      ch = giorno.value.charAt(i);
      for (j = 0;  j < checkOK.length;  j++)
       if (ch == checkOK.charAt(j))
       {
        break;
       }
       if (j == checkOK.length)
       {
         alert ("Insert a valid day in the field  '"+string+"'")
         giorno.focus();
         return(false);
       }
     }
    }
    if (eval(giorno.value) == 0)
    {
       alert ("Insert a valid day in the field  '"+string+"'")
       giorno.focus();
       return(false);
    }
    if (mese.value.length > 0)
    {
     for (i = 0;  i < mese.value.length;  i++)
     {
       ch = mese.value.charAt(i);
       for (j = 0;  j < checkOK.length;  j++)
         if (ch == checkOK.charAt(j))
         {
             break;
         }
         if (j == checkOK.length)
         {
          alert ("Insert a valid month in the field  '"+string+"'")
          mese.focus();
          return(false);
         }
      }
    } 
    if (anno.value.length > 0)
     {
       for (i = 0;  i < anno.value.length;  i++)
       {
         ch = anno.value.charAt(i);
         for (j = 0;  j < checkOK.length;  j++)
           if (ch == checkOK.charAt(j))
           {
             break;
           }
           if (j == checkOK.length)
           {
             alert ("Insert a valid year in the field  '"+string+"'")
             anno.focus();
             return(false);
           }
        }
      }
      if ((eval(anno.value)== 2000) || (eval(anno.value) == 2004) || (eval(anno.value)==2008) || (eval(anno.value) == 2012) || (eval(anno.value) == 2016))
         mesi[2]="29";
      else
         mesi[2]="28";
      if (eval(mese.value) < 1 || eval(mese.value) > 12)
      {
         alert ("Insert a valid month in the field  '"+string+"'")
         mese.focus();
         return(false);
      }
      if (eval(giorno.value) > mesi[eval(mese.value)])
      {
         alert ("Insert a valid day in the field  '"+string+"'")
         giorno.focus();
         return(false);
      }
      if (eval(anno.value) < 1900 || eval(anno.value) > 2020)
      {
         alert ("Insert a valid year in the field  '"+string+"'")
         anno.focus();
         return(false);
      }
   return(true);
  }


  function ctrtime(hour,minute,string,flag)
  {
    var ora=hour;
    var minuti=minute;
    var checkOK = "0123456789";

  if (eval(flag) == 0 && (ora.value.length == 0 && minuti.value.length == 0))
  {
    return(true);
  }else{
    if (ora.value.length == 0 || minuti.value.length == 0)
    {
      alert ("Insert a valid time in the field  '"+string+"'");
      ora.focus();
      return(false);
    }
  }
  if (ora.value.length > 0)
   {
    for (i = 0;  i < ora.value.length;  i++)
    {
     ch = ora.value.charAt(i);
     for (j = 0;  j < checkOK.length;  j++)
       if (ch == checkOK.charAt(j))
       {
        break;
       }
       if (j == checkOK.length)
       {
         alert ("Insert a valid time in the field '" + string+"'") 
         ora.focus();
         return(false);
       }
      }
  }
  if (minuti.value.length > 0)
   {
    for (i = 0;  i < minuti.value.length;  i++)
    {
     ch = minuti.value.charAt(i);
     for (j = 0;  j < checkOK.length;  j++)
       if (ch == checkOK.charAt(j))
       {
        break;
       }
       if (j == checkOK.length)
       {
         alert ("Insert a valid time in the field  '" + string+"'") 
         minuti.focus();
         return(false);
       }
      }
  }
  if (eval(ora.value)>23)
  {
      alert ("Insert a valid time in the field  '" + string+"'") 
      ora.focus();
      return(false);
  }
  if (eval(minuti.value)>59)
  {
      alert ("Insert a valid time in the field  '" + string+"'") 
      minuti.focus();
      return(false);
  }
  return(true);
 }