function switch_visibility(element_id, display_type) {
   
   var el_form = document.getElementById(element_id);

   switch (display_type) {
      case "block":
         break;
      case "table":
         display_type = "table-row";
         break;
      default:
         display_type = "block";
      }

   if (el_form.style.display == "none") {
      el_form.style.display = display_type;
      }
   else {
      el_form.style.display = "none";
      }
}

function check_order_form() {
   var terms_checkbox = document.getElementById('terms_agreement');
   var terms_submit = document.getElementById('ordersend');

   if (terms_checkbox.checked)
      terms_submit.disabled = false;
   else
      terms_submit.disabled = true;
}

function show_checque(){
	
	var checque = document.getElementById('checque').style;
	
	if(checque.display == "none"){
		checque.display = "table-row";
		//document.getElementById('checque').innerHTML = '<br /><input type="text" name="checque" /> Zde uveďte částku, kterou chcete hradit šekem.<br /><br />';
	}
	else{
		checque.display = "none";
	}
}

function recalc(val){
	
	val2 = eval("document.forms.orderform.checque.value");
	
	fin = (val - val2);
	if(fin < 0)	fin = "Přeplatek " + (fin*-1);
	if(fin > 0)	fin = "Doplatek " + fin;
	
	document.forms.orderform.checque_2.value = fin;
	
	
}