function clear_err (field_name) {
      /*document.getElementById(field_name).style.visibility="hidden";*/
      //document.getElementById(field_name).style.overflow="hidden";
      //document.getElementById(field_name).style.width="0px";
      document.getElementById(field_name).style.display="none";
}

function show_err (field_name, tekst) {
      //document.getElementById(field_name).style.visibility="visible";
      
      if (tekst != undefined) {
         $('#' + field_name).text(tekst);
      }
      document.getElementById(field_name).style.display="inline";
}


function spr_all() {
   result=   spr_name() && spr_telefon () && spr_email () && spr_opis ();
   
   if (result) 
   {
      $.post(
          "form.php",
          
          {
            txtCaptcha:$('#txtCaptcha').val(), 
            imie:$('#imie').val(),
            telefon:$('#telefon').val(),
            email:$('#email').val(),
            opis:$('#opis').val()
          },
          
          function(returned_data)
          {
            var message = returned_data.slice(1);
            //alert(message);
            //$('#message').text(returned_data);
            if (returned_data.slice(0,1) == "0") //failure
            {
                //alert("fail");
                $("#imgCaptcha").attr("src", "create_image.php?asdf="+Math.random());
                $("#message").attr("style", "color:red;");
            }
            else //success
            {
                //alert("success");
                $("#message").attr("style", "color:green;");
                $("#sendbutton").attr("disabled","disabled");
            }
            $("#message").text(message);
            
          }
      );
   }
   //if (!result) alert ("Wypełnij wszystkie pola!");
}


function spr_name () {

   name=document.getElementById("imie").value;
   if (name=="" || is_white_space(name) || !is_safe(name)) {
   
   
      if (!is_safe(name)) {
         show_err("err_name", $('#niepoprawne_znaki').text());
      }
      else {
         show_err("err_name", $('#wypelnij_to').text());
      }
      return false;
   } 
   else {
   
      
      clear_err("err_name");
      return true;
   }
}



function spr_telefon () {
   var filter = /^[+]{0,1}([0-9\ \-]){7,}$/;


   telefon=document.getElementById("telefon").value;
   if (telefon=="")  {
      show_err("err_telefon");
      return false;
   } 
   else if (!filter.test(telefon)) {
      show_err("err_telefon2");
   }
    else {
      clear_err("err_telefon");
      clear_err("err_telefon2");
      return true;
   }
   
}

function spr_email () {
   var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

   email=document.getElementById("email").value;
   if (email != "" && !filter.test(email))  {
      show_err("err_email2");
      return false;
   } 
   else {
      clear_err("err_email2");
      return true;
   }
   
   
}

function spr_opis () {

   opis=document.getElementById("opis").value;
   if (opis=="" || !is_safe(opis))  {
      if (!is_safe(opis)) {
         show_err("err_opis", $('#niepoprawne_znaki').text());
      }
      else {
         show_err("err_opis", $('#wypelnij_to').text());
      }
      return false;
   } 
    else {
      clear_err("err_opis");
      return true;
   }
}

function is_safe(tekst) {
   bad= "><;&()][{}";
   for(i=0;i<tekst.length;i++) {
      var znak = tekst.charAt(i);
      if (bad.indexOf(znak) != -1) {
         return false;
      }
   
   }
   
   return true;
}

function is_white_space (tekst) {

   bad= "\n\r\t";
   for(i=0;i<tekst.length;i++) {
      var znak = tekst.charAt(i);
      if (bad.indexOf(znak) != -1) {
         return true;
      }
   
   }
   
   return false;

}