/* AJAX */
/*
ajax uzklausos funkcija
url - uzklausos adresas su parametrais
function_name - funkcijos, kuria vykdyti gavus rezultata
element_id - susieto elemento id
element_value - susieto elemento reiksme
*/
function ajax(url, function_name, element_id, element_value) {
  http_request = false;
  // Mozilla, Safari, ...
  if (window.XMLHttpRequest) {
    http_request = new XMLHttpRequest();
    if (http_request.overrideMimeType) {
      http_request.overrideMimeType('text/xml');
    }
  }
  // IE
  else if (window.ActiveXObject) {
    try {
      http_request = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e) {
      try {
        http_request = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch (e) {
      }
    }
	}
	if (!http_request) {
	  return false;
	}
	switch (function_name) {
	  case "ajax_options": http_request.onreadystatechange = function() { ajax_options(http_request, element_id, element_value); }; break;
	}
	http_request.open('GET', url, true);
	http_request.send(null);
}

/* Funkcija, atnaujinanti nurodyto select elemento options irasus */
function ajax_options(http_request, selection_id, selection_value) {
  if (http_request.readyState == 4) {
    if (http_request.status == 200) {
      /* Isvalomas tekstas */
      var output = http_request.responseText;
      /* Sukuriama visu elementu seka */
      output = output.split('<n>');
      /* Nustatomas select elementas */
      var selection = document.getElementById(selection_id);
      /* Salinami visi buve options irasai isskyrus pirmaji */
      for (var i = selection.length - 1; i > 0; i --) {
        selection.remove(i);
			}
			/* Tikrinama ar selection_value yra reiksmiu sarasas ar tik viena reiksme */
			if (typeof(selection_value) == "string" && selection_value.match(',')) {
			  selection_value = selection_value.split(',');
			}
      /* Jeigu gautas tekstas */
			if (output != '') {
        /* Kuriami nauji options elementai */
        for (var i = 0; i < output.length; i ++) {
          option_data = output[i].split('<s>');
          option = document.createElement('OPTION');
          option.value = option_data[0];
          if (selection_value && (option.value == selection_value || in_array(option.value, selection_value))) {
            option.selected = 'selected';
          }
          option.innerHTML = option_data[1];
          selection.appendChild(option);
        }
        /* Aktyvinamas select elementas */
        selection.disabled = false;
        return true;
      }
      /* Jeigu tekstas negautas */
      else {
        /* Nuaktyvinamas select elementas */
        selection.disabled = true;
        return true;
			}
    }
    else {
      return false;
    }
  }
}

function get_education_professions(education_profession_value) {
  var education_category = document.getElementById('education_category');
  var education_profession = document.getElementById('education_profession');

  if (education_category.value != '') {
		option = document.createElement('OPTION');
		option.value = '';
		option.innerHTML = 'Palaukite...';
		education_profession.appendChild(option);
		option.selected = 'selected';
		education_profession.disabled = true;

		ajax('_ajax/get_options.php?table=professions&parent_id='+education_category.value+'&order_first=name', 'ajax_options', 'education_profession', education_profession_value);
	}
	else {
    for (i = education_profession.length - 1; i > 0; i --) {
      education_profession.remove(i);
    }
    education_profession.disabled = true;
	}
}

function get_experience_positions(experience_position_value) {
  var experience_category = document.getElementById('experience_category');
  var experience_position = document.getElementById('experience_position');

  if (experience_category.value != '') {
		option = document.createElement('OPTION');
		option.value = '';
		option.innerHTML = 'Palaukite...';
		experience_position.appendChild(option);
		option.selected = 'selected';
		experience_position.disabled = true;

		ajax('_ajax/get_options.php?table=positions&parent_id='+experience_category.value+'&order_first=name', 'ajax_options', 'experience_position', experience_position_value);
	}
	else {
    for (i = experience_position.length - 1; i > 0; i --) {
      experience_position.remove(i);
    }
    experience_position.disabled = true;
	}
}

function get_computer_programs(computer_program_value) {
  var computer_category = document.getElementById('computer_category');
  var computer_program = document.getElementById('computer_program');

  if (computer_category.value != '') {
		computer_program.disabled = true;

		ajax('_ajax/get_options.php?table=programs&parent_id='+computer_category.value+'&order_first=name', 'ajax_options', 'computer_program', computer_program_value);
	}
	else {
    for (i = computer_program.length - 1; i > 0; i --) {
      computer_program.remove(i);
    }
    computer_program.disabled = true;
	}
}

/* IN ARRAY */
function in_array(needle, haystack) {
  for (h in haystack) {
    if (haystack[h] == needle) {
      return true;
    }
  }
  return false;
}