var http = false;
	if (window.XMLHttpRequest) {
		http = new XMLHttpRequest(); //Mozilla, Safari,Opera
	} else if (window.ActiveXObject) {
		try {
			http = new ActiveXObject("Msxml2.XMLHTTP"); //IE 5
		} catch (e) {
			try {
				http = new ActiveXObject("Microsoft.XMLHTTP"); //IE 6
			} catch (e) {}
		}
	}
	if (!http) {
		alert('Kann keine XMLHTTP-Instanz erzeugen');
	}

	function buchen(id){
		http.open('GET', 'inc/buy.php?id='+id, true);
		http.onreadystatechange = ausgeben;
		http.send(null);
	}

	function ausgeben() {
		if (http.readyState == 4) {
		document.getElementById("buynow").innerHTML =
		http.responseText;
		}
	}
	
	function change(select,category){
		var datum = select.options[select.options.selectedIndex].value;
		document.getElementById('datum_1').value = datum;
		
		if(category == 1) {
				document.getElementById('amount_1').value = '10.00';
				document.getElementById('item_name_1').value = 'reservierbarer Bereich';
			}
		if(category == 2) {
			document.getElementById('amount_1').value = '20.00';
			document.getElementById('item_name_1').value = 'Loge';
			
		}
		return;
	}
	

	function checkform(){
		if(document.getElementById('datum').options[document.getElementById('datum').options.selectedIndex].value == ''){
			alert('Bitte ein Datum angeben!');
			return;
		}
		if(isInteger(document.getElementById('menge').value) == false || document.getElementById('menge').value < 1 ){
			alert('Bitte eine Menge > 0 angeben!');
			return;
		}
		document.getElementById('reservierung').submit();
	}
	
	function isInteger (s){
      var i;

      if (isEmpty(s))
      if (isInteger.arguments.length == 1) return 0;
      else return (isInteger.arguments[1] == true);

      for (i = 0; i < s.length; i++)
      {
         var c = s.charAt(i);

         if (!isDigit(c)) return false;
      }

      return true;
   }

	function isEmpty(s){
      return ((s == null) || (s.length == 0))
  }

  function isDigit (c){
      return ((c >= "0") && (c <= "9"))
  }