function selectOption(radio_id) {
  document.getElementById('radio_' + radio_id).checked = true;
}

function alertContents_update_cart() {
  //Indicates a complete response
  if (http_request.readyState == 4) {
    //Indicates that the status of the response is OK
    if (http_request.status == 200) {
	    var xmldoc = http_request.responseXML;
	    var results = xmldoc.documentElement.getElementsByTagName("result");
	    var category = xmldoc.documentElement.getElementsByTagName("category")[0];
      for(var x = 0; x < results.length; x++) {
        var myElement = document.getElementById('label_' + results[x].getAttribute("id"));
        var insideText = " " + results[x].firstChild.data;
        var priceDifference = results[x].getAttribute("price");
        if ( priceDifference < 0 ) {
          insideText = insideText + " [Subtract $" + Math.abs(priceDifference) + "]";
        }
        else if ( priceDifference > 0 ) {
          insideText = insideText + " [Add $" + Math.abs(priceDifference) + "]";
        }
        myElement.innerHTML = insideText;
        if( results[x].getAttribute("checked") == "true" ) {
          selectOption(results[x].getAttribute("id"));
        }
      }
      makeRequest('remote_calls/get_cart.php','get_cart');
      new Effect.Highlight(document.getElementById('overview_price'), {queue: {position: 'end', scope: 'price'}, duration: 2});
      new Effect.Highlight(document.getElementById('item_' + category.firstChild.data), {queue: {position: 'end', scope: 'item'}, duration: 2});
    } else {
      alert('There was a problem with the request.');
    }
  }
}

function alertContents_get_cart() {
 //Indicates a complete response
 if (http_request.readyState == 4) {
  //Indicates that the status of the response is OK
  if (http_request.status == 200) {
    var xmldoc = http_request.responseXML;
    var parts = xmldoc.documentElement.getElementsByTagName("part");
    var price = xmldoc.documentElement.getElementsByTagName("price")[0].firstChild.data;
    for(var x = 0; x < parts.length; x++) {
      document.getElementById('item_' + parts[x].getAttribute("category_id")).innerHTML = parts[x].firstChild.data;
    }
    document.getElementById('overview_price').innerHTML = "$" + price;
    document.getElementById('cart_price').value = price;
  }
 }
}

function alertContents_learn_more() {
 //Indicates a complete response
 if (http_request.readyState == 4) {
  //Indicates that the status of the response is OK
  if (http_request.status == 200) {
    document.getElementById('learn_more').innerHTML = http_request.responseText;   
    new Effect.Highlight(document.getElementById('learn_more'), {queue: {position: 'end', scope: 'learn', limit:1}, duration: 2});
  }
 }
}