var req;

    var show_cart_Url = "cart.php?action=show";    
    function show_cart() {
      try {
        if( window.XMLHttpRequest ) {
          req = new XMLHttpRequest();
        } else if( window.ActiveXObject ) {
          req = new ActiveXObject( "Microsoft.XMLHTTP" );
        } else {
          //alert( "Ajax: not supported." );
        }
        req.open( "GET", show_cart_Url, true );
        req.onreadystatechange = cartCallbackFkt;
        req.send( null );
      } catch( e ) {
        //alert( "Error: " + e );
      }
    }
    
    var add_to_cart_Url = "cart.php?action=add";
    function add_to_cart(id, qt) {
      try {
        if( window.XMLHttpRequest ) {
          req = new XMLHttpRequest();
        } else if( window.ActiveXObject ) {
          req = new ActiveXObject( "Microsoft.XMLHTTP" );
        } else {
          //alert( "Ajax: not supported." );
        }
        req.open( "GET", add_to_cart_Url +"&id="+id+"&qt="+qt , true );
        req.onreadystatechange = cartCallbackFkt;
        req.send( null );
      } catch( e ) {
        //alert( "Error: " + e );
      }
    }

    var set_shipping_costs_Url = "cart.php?action=shipping";
    function set_shipping_costs(sc) {
      try {
        if( window.XMLHttpRequest ) {
          req = new XMLHttpRequest();
        } else if( window.ActiveXObject ) {
          req = new ActiveXObject( "Microsoft.XMLHTTP" );
        } else {
          //alert( "Ajax: not supported." );
        }
        req.open( "GET", set_shipping_costs_Url +"&sc="+sc , true );
        req.onreadystatechange = kasseCallbackFkt;
        req.send( null );
      } catch( e ) {
        //alert( "Error: " + e );
      }
    }	

    var show_kasse_Url = "cart.php?action=kasse";
    function show_kasse() {
      try {
        if( window.XMLHttpRequest ) {
          req = new XMLHttpRequest();
        } else if( window.ActiveXObject ) {
          req = new ActiveXObject( "Microsoft.XMLHTTP" );
        } else {
          //alert( "Ajax: not supported." );
        }
        req.open( "GET", show_kasse_Url , true );
        req.onreadystatechange = kasseCallbackFkt;
        req.send( null );
      } catch( e ) {
        //alert( "Error: " + e );
      }
    }

    var add_kasse_item_Url = "cart.php?action=add_kasse_item";
    function add_kasse_item(id, qt) {
      try {
        if( window.XMLHttpRequest ) {
          req = new XMLHttpRequest();
        } else if( window.ActiveXObject ) {
          req = new ActiveXObject( "Microsoft.XMLHTTP" );
        } else {
          //alert( "Ajax: not supported." );
        }
        req.open( "GET", add_kasse_item_Url+"&id="+id+"&qt="+qt , true );
        req.onreadystatechange = kasseCallbackFkt;
        req.send( null );
      } catch( e ) {
        //alert( "Error: " + e );
      }
    }

    var add_zahlart_Url = "cart.php?action=add_zahlart";
    function add_zahlart(pay) {
      try {
        if( window.XMLHttpRequest ) {
          req = new XMLHttpRequest();
        } else if( window.ActiveXObject ) {
          req = new ActiveXObject( "Microsoft.XMLHTTP" );
        } else {
          //alert( "Ajax: not supported." );
        }
        req.open( "GET", add_zahlart_Url+"&pay="+pay , true );
        req.onreadystatechange = kasseCallbackFkt;
        req.send( null );
      } catch( e ) {
        //alert( "Error: " + e );
      }
    }

    function cartCallbackFkt() {
      if( 4 == req.readyState ) {
        if( 200 != req.status ) {
          //alert( "Error " + req.status + ": " + req.statusText );
        } else {
          //alert( req.responseText );
          var cart_table = req.responseText;
          document.getElementById("cart").innerHTML = cart_table;
        }
      }
    }

    function kasseCallbackFkt() {
      if( 4 == req.readyState ) {
        if( 200 != req.status ) {
          //alert( "Error " + req.status + ": " + req.statusText );
        } else {
          //alert( req.responseText );
          var cart_content_table = req.responseText;
          document.getElementById("cart_content").innerHTML = cart_content_table;
        }
      }
    }