function createAjax() {
  var ajax = false;

  if(window.XMLHttpRequest) {
    ajax = new XMLHttpRequest();
  } else if(window.ActiveXObject) {
    ajax = new ActiveXObject("Microsoft.XMLHTTP");
  }

  return ajax;
}

function isAjaxReady(ajax) {
  if (ajax.readyState == 4) {
    return true;
  } else {
    return false;
  }
}


/*----- CATALOGUE CONTENT ------*/
var http = createAjax();
function sendRequest(my_action,my_var){
	// dodavanje u selektor i saljem $_REQUEST promenljivu add_item skriptu sr_selektor.php
  if(my_action == 'display_level_2'){
 	 if (http) {
  	 http.open('get', 'pages_products/ajax_catalogue_content.php?display_level_2='+my_var);
   	 http.onreadystatechange = handleResponse;
 	 }
  }
  
  if(my_action == 'display_level_3'){
 	 if (http) {
  	 http.open('get', 'pages_products/ajax_catalogue_content.php?display_level_3='+my_var);
   	 http.onreadystatechange = handleResponse;
 	 }
  } 
  
  if(my_action == 'close_menu'){
 	 if (http) {
  	 http.open('get', 'pages_products/ajax_catalogue_content.php?close_menu='+my_var);
   	 http.onreadystatechange = handleResponse;
 	 }
  } 
  
  if(my_action == 'display_product_photo'){
 	 if (http) {
  	 http.open('get', 'pages_products/ajax_catalogue_content.php?display_product_photo='+my_var);
   	 http.onreadystatechange = handleResponse;
 	 }
  } 
  
	
  http.send('');
} 

/* Handle za Selector */
function handleResponse() {
    if (http.readyState == 4) {
      response = http.responseText;
      document.getElementById('AJAX_catalogue_container').innerHTML = response;
    }else if(http.readyState == 1){
      document.getElementById('AJAX_catalogue_container').innerHTML = "<div id='transparency' style='text-align:center;padding:4px;border:0px;'><img src=site_images/loading.gif></div>";
	}

}