function isIE() {
   return (document.all && navigator.userProfile && !isOpera()
           && navigator.appName == 'Microsoft Internet Explorer') ?
           true : false;
}

function isOpera() {
   return (window.opera) ? true : false;
}

//******************************************************************//
//funkce specificke pro e-shop, validacni, ruzne dialogy atd. jinde nepouzitelne
//******************************************************************//

//test vyplneni udaju v login formu
function validate_login_form(form) {
   if(form.login.value=="") {
      alert(js_text["login_no_login"]);
      return false;
   }
   else if(form.password.value=="") {
      alert(js_text["login_no_password"]);
      return false;
   }
   else {
      form.javascript.value="on";
      form.password.value=hexMD5(form.password.value);
      return true;
   }
}

// test vyplneni udaju ve forget formulari
function validate_forget_form(form) {
   if(form.forget.value == "") {
      alert(js_text["forget_no_login"]);
      return false;
   }
   return true;
}

//test spravneho poctu pri vkladani do kosiku
function validate_count(form) {
   if(form.insert_count.value<1 || form.insert_count.value>10000 || isNaN(form.insert_count.value) || form.insert_count.value.indexOf(".")==1) {
      alert(js_text["buy_bad_number"]);
      return false;
   }
   return true;
}

//test editace poctu v kosiku	
function validate_edit_count(form) {
   if(form.edit_count.value<1 || isNaN(form.edit_count.value) || form.edit_count.value.indexOf(".")==1) {
      alert(js_text["buy_bad_number"]);
      return false;
   }
   return true;
}

//test vyhledavaciho formulare	
function validate_search(form) {
   if(form.key_words.value=='' || form.key_words.value.length<2) {
      alert(js_text["search_bad_keyword"]);
      return false;
   }
   return true;
}



//zobrazeni a skryti vyhledavaciho formulare
function switch_adv_form(id) {
	var adv_form = document.getElementById(id);
	if(adv_form.style.display == "none") {
		adv_form.style.display = "block";
	}
	else {
		adv_form.style.display = "none";
	}
}

//zobrazeni a skryti napovedy u vyhledavaciho formulare
function switch_help(id) {
	var help = document.getElementById(id);
	if(help.style.display == "block") {
		help.style.display = "none";
	}
	else {
		help.style.display = "block";    	 
	}   
}

//test vstupnich dat v pokrocilem vyhledavani	
function validate_adv_search(form) {
	if(form.key_words.value=='' || form.key_words.value.length<2) {
		alert(js_text["search_bad_keyword"]);
		return false;
	}
	else if (
      form.item_name.checked == false && 
      form.short_text.checked == false && 
      form.long_text.checked == false && 
      form.code.checked == false && 
      form.redaction.checked == false && 
      form.news.checked == false )
   {
		alert(js_text["search_no_attr"]);
		return false;
	}
	return true;
}	

//potvrzeni objednavky	
function order_confirmation() {
   // zkontroluj zda je vybran zpusob dodani
   deliver_type_selected = false;
   es = document.getElementsByName("deliver_type");
   for(i=0; i<es.length; i++) {
      deliver_type_selected |= es[i].checked;
      if(es[i].checked) {
         return eshop_show_deliver_warning(es[i].value);
      }
   }
   // pokud zpusob dodani neni zadan, vrat se
   if(!deliver_type_selected) {
      alert(js_text["buy_choose_deliver"]);
      return false;
   }
   // potvrzeni objednavky
//	return window.confirm(js_text["buy_order_confirm"]);
}

//potvrzeni vymazu z kosiku
function delete_confirm_cart() {
   logic = window.confirm(js_text["buy_delete_confirm"]);
   return logic;
}