//function that gets the page id from the URL
function getURLParam(strParamName){
  var strReturn = "";
  var strHref = window.location.href;
  if ( strHref.indexOf("?") > -1 ){
  	var strQueryString = strHref.substr(strHref.indexOf("?")).toLowerCase();
    var aQueryString = strQueryString.split("&");
    for ( var iParam = 0; iParam < aQueryString.length; iParam++ ){
      if (aQueryString[iParam].indexOf(strParamName.toLowerCase() + "=") > -1 ){
        var aParam = aQueryString[iParam].split("=");
        strReturn = aParam[1];
        break;
      }
    }
  }
  return unescape(strReturn);
}



//http://developer.apple.com/internet/webcontent/xmlhttpreq.html

// To convert retrieved XML data into renderable HTML content, 
// rely on the client-side Document Object Model (DOM) to read
// the XML document node tree and compose HTML elements that 
// the user sees.
function loadXMLDoc(url) {
	xmlhttp=null;
	// code for Mozilla, Safari, etc.
	if (window.XMLHttpRequest) {
  		xmlhttp = new XMLHttpRequest();
  	}
	// code for IE
	else if (window.ActiveXObject) {
  		xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
  	}

	if (xmlhttp!=null) {
  		xmlhttp.onreadystatechange=onResponse;
  		xmlhttp.open("GET",url,true);
  		xmlhttp.send(null);
 	} else {
  		alert("Your browser does not support XMLHTTP.");
  	}
}

function checkReadyState(obj) {
  // Use the readyState property inside the event handler 
  // function that processes request object state change 
  // events. While the object may undergo interim state 
  // changes during its creation and processing, the value 
  // that signals the completion of the transaction is 4.
  if(obj.readyState == 4) {
  
  	// You still need more confirmation that the transaction 
  	// completed successfully before daring to operate on the 
  	// results.  Respective property values of 200 and OK indicate success.
    if(obj.status == 200) {
    	return true;
    } else {
    	alert("There was a problem retrieving the XML data:\n" + obj.statusText);
    }
  }
}





function onResponse() {
  if(checkReadyState(xmlhttp)) {
  
  // get the page id from URL
  var id = getURLParam("id");
  if((id.substring(1,2)) == "#") {
  	id = id.substring(0,1);
  } else {
  	id = id.substring(0,2);
  }
  var cid = parseInt(id);
  
  var response = xmlhttp.responseXML.documentElement;
  var x = response.getElementsByTagName("nav");
  
  var totalNumPag = x.length;
  
  if((isNaN(cid)) || (cid == 1)) {
  	nextPage = 1;
  	//gets next node from XML
  		var n_title = x[nextPage].getElementsByTagName('linkNext')[0].firstChild.data;
  		var n_pNumberStr = x[nextPage].getElementsByTagName('pageNumber')[0].getAttribute("type");
  		var n_pNumber = x[nextPage].getElementsByTagName('pageNumber')[0].firstChild.data;
  		var n_link = x[nextPage].getElementsByTagName('linkURL')[0].firstChild.data;
		var goNext = n_link + n_pNumberStr + (nextPage + 1);
  } else {
   	if(cid == 60) {
   	} else {
     	nextPage = cid;
   			var n_title = x[nextPage].getElementsByTagName('linkNext')[0].firstChild.data;
  			var n_pNumberStr = x[nextPage].getElementsByTagName('pageNumber')[0].getAttribute("type");
  			var n_pNumber = x[nextPage].getElementsByTagName('pageNumber')[0].firstChild.data;
  			var n_link = x[nextPage].getElementsByTagName('linkURL')[0].firstChild.data;
 		
 			var goNext = n_link + n_pNumberStr + (nextPage + 1);
   	}
   }
   
   
  if((isNaN(cid)) || (cid == "1") ) {
  
  } else {
  	prevPage = cid - 2;
  	
  		//gets previous node from XML
 	 	var p_title = x[prevPage].getElementsByTagName('linkText')[0].firstChild.data;
  		var p_pNumberStr = x[prevPage].getElementsByTagName('pageNumber')[0].getAttribute("type");
  		var p_pNumber = x[prevPage].getElementsByTagName('pageNumber')[0].firstChild.data;
  		var p_link = x[prevPage].getElementsByTagName('linkURL')[0].firstChild.data;
  		//window.alert( p_link);
  	
  		var goPrev = p_link + p_pNumberStr + (prevPage + 1);
  }
    
  //creates link
  function createLink(link, title) {
  	var newLink=document.createElement('a');
  	newLink.setAttribute('href',link);
  	// - use 'className' to create the equivalent of class="contrast"
  	newLink.className='right';
  
  	var linkText=document.createTextNode(title);
  	newLink.appendChild(linkText);
  
  return newLink;
  }
  
  //creates link for the footer
  function createLink1(link, title) {
  	var newLink=document.createElement('a');
  	newLink.setAttribute('href',link);
  	// - use 'className' to create the equivalent of class="contrast"
  	newLink.className='left';
  
  	var linkText=document.createTextNode(title);
  	newLink.appendChild(linkText);
  
  return newLink;
  }
  
  //creates link
  function createLink2(link, title) {
  	var newLink=document.createElement('a');
  	newLink.setAttribute('href',link);
  	// - use 'className' to create the equivalent of class="contrast"
  	newLink.className='left';
  
  	var linkText=document.createTextNode(title);
  	newLink.appendChild(linkText);
  
  return newLink;
  }
  
  nextLink = createLink(goNext, n_title);
  backLink = createLink1(goPrev, p_title);
  
  //Footer  
  nextLink2 = createLink(goNext, n_title);
  backLink2 = createLink1(goPrev, p_title);
  
  if((isNaN(cid)) || (cid == "1")) {
   	 document.getElementById("CurrentPage").innerHTML = "&nbsp;";
   	 document.getElementById('Next').appendChild(nextLink);
 	 document.getElementById("totalNumberPages").innerHTML = "&nbsp;";
  	 document.getElementById('Next').appendChild(nextLink);
  	 
  	 document.getElementById("totalNumberPages1").innerHTML = "&nbsp;";
  	 document.getElementById('Next1').appendChild(nextLink2);
   
   } else {
   		if(cid == 60) {
   			document.getElementById('Prev').appendChild(backLink);
 	 		document.getElementById("CurrentPage").innerHTML = "";
 	 		document.getElementById("totalNumberPages").innerHTML = "&nbsp;";
 	 		
 	 		document.getElementById('Prev1').appendChild(backLink2);
  			document.getElementById("CurrentPage1").innerHTML = "";
  			document.getElementById("totalNumberPages1").innerHTML = "&nbsp;";
   		} else {
 	 			document.getElementById('Prev').appendChild(backLink);
 	 			document.getElementById("CurrentPage").innerHTML = "|";
 	 			document.getElementById("totalNumberPages").innerHTML = "&nbsp;";
  				document.getElementById('Next').appendChild(nextLink);
  				
  				document.getElementById('Prev1').appendChild(backLink2);
  				document.getElementById("CurrentPage1").innerHTML = "|";
  				document.getElementById("totalNumberPages1").innerHTML = "&nbsp;";
  				document.getElementById('Next1').appendChild(nextLink2);
 		 }
    }
  
  
  }
}