function updateDisplay(pUpdateWhat, pComboRead, pCallbackFunction) {
	//PURPOSE: Decide what elements are going to be updated on the page.
	
	//Base url of XML feeds
	var url = "data.php?";
	
	//Decide what URL to use
	switch(pUpdateWhat) { 
		case "province":
			url = url + "a=province&country=" + comboSelectedValue(pComboRead);
			break;
		case "town":
			url = url + "a=town&province=" + comboSelectedValue(pComboRead);
			break;
		case "urban":
			url = url + "a=urban&town=" + comboSelectedValue(pComboRead);
			break;
		case "proptype":
			url = url + "a=proptype&country=" + comboSelectedValue(pComboRead);
			break;	
	}
	url = url + "&time=" + new Date().getTime();  //IE Cache Prevention

//Create AJAX request
	var request = null;
	try {
		request = new XMLHttpRequest(); 
	} catch (tryms) {
		try {
			request = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (otherms) {
			try {
				request = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (failed) {
				request = null;
			}
		}
	}
	
	//Check AJAX is initialised
	if (request == null) { 
		alert("Error initialising AJAX");
	}
	
	//Send the AJAX request
	request.open("GET", url, true);
	request.onreadystatechange = function () { 
		if (request.readyState == 4) {
			if (request.status == 200) {
				eval(pCallbackFunction + '(request.responseXML)');
			}
		}
	}
	
	request.send(null);
 
}

//COMBO UPDATES

function updateProvinceCombo(pXML) {
	updateComboBox("province", "- Any -", "provinces", "province", pXML);
}

function updateTownCombo(pXML) {
	updateComboBox("town", "- Any -", "towns", "town", pXML);
}

function updateUrbanCombo(pXML) {
	updateComboBox("urban", "- Any -", "urbans", "urban", pXML);
}

function updatePropTypeCombo(pXML) {
	updateComboBox("ptyp", "- Any -", "proptypes", "proptype", pXML);
}

//COMBO BOX SUPPORT PARTS

function updateComboBox(pElementName, pElementDefault, pRootName, pItemsName, pXML) {
	//PURPOSE: Clear combo and add XML records in pre-determined format
	
	//Update ANY combobox
	comboClear(pElementName)
	comboAddOption(pElementName, "-", pElementDefault);
	
	//Process XML document
	var xmlDoc = pXML;
	var root = xmlDoc.getElementsByTagName(pRootName)[0];
	var items = root.getElementsByTagName(pItemsName);
	
	//Cycle Through adding items to combo
	for (var i = 0; i < items.length; i++) {
		var branch = items[i];
		var pcode = branch.getElementsByTagName("code")[0].firstChild.nodeValue;
		var pname = branch.getElementsByTagName("name")[0].firstChild.nodeValue;
		
		//Add To Combo Box
		//alert(pcode + " " + pname);
		comboAddOption(pElementName, pcode, pname);
	}
}

function comboAddOption(cmbElement, optionlabel, optionvalue) {
	//PURPOSE: Add option to combo box
	var opt = document.createElement('option');
	opt.value = optionlabel;
	opt.text = optionvalue;
	var cmb = document.getElementById(cmbElement);
	try {
		cmb.add(opt, null); // standards compliant
	} catch(ex) {
		cmb.add(opt);  // IE only
	}
}

function comboClear(cmbElement) {
	//PURPOSE: Clear all options from combo box
	i = 0;
	var cmb = document.getElementById(cmbElement);
	cmb.options.length=0;
}

function comboSelectedValue(cmbElement) {
	//PURPOSE: Select an existing combo box
	var sindex = document.getElementById(cmbElement).selectedIndex;
	var sval = document.getElementById(cmbElement).options[sindex].value;
	return sval;
}


//DAYS OF MONTH PARTS

function updateDays(readfrom, writeto) {
	
	//Reference Page Elements
	var el = document.getElementById(readfrom);
	var wt = document.getElementById(writeto);
	var dv = el.value;
	
	//Get selected dateparts
	var parts = dv.split("-");
	var daysMonth = 32 - new Date(parts[1], parts[0]-1, 32).getDate();
	alert(daysMonth);
	
	//Clear list
	for (var i = wt.options.length-1; i>=0; i--) {
		wt.options[i] = null;
	  }
	  wt.selectedIndex = -1;
	
	//Add Blank
	var opt = document.createElement("OPTION");
	opt = new Option("...", "...");
	opt.id = "-";
	wt.add(opt);
	//Fill List
	for (var i = 1; i<=daysMonth; i++) {
		opt = new Option(i, i);
		opt.id = i;
		wt.add(opt);
	}
}