// Common variables
var READYSTATE_UNINITIALIZED = 0;
var READYSTATE_LOADING = 1;
var READYSTATE_LOADED = 2;
var READYSTATE_INTERACTIVE = 3;
var READYSTATE_COMPLETE = 4;

// Common values for HTTP status codes
var HTTPSTATUS_OK = 200;
var HTTPSTATUS_NOTFOUND = 404;
var HTTPSTATUS_SERVERERROR = 500;

// create http request object
function GetXmlHttpRequestObject() {
    
    if (window.XMLHttpRequest) {
        xmlHttpObj = new XMLHttpRequest();
    }
    else
    {
        try
        {
            xmlHttpObj = new ActiveXObject("Microsoft.XMLHTTP");
        }
        catch(e)
        {
            xmlHttpObj = new ActiveXObject("Msxml2.XMLHTTP");
        }
     }
     
     return xmlHttpObj;
}

function AJAXrequest(url, f) {
    var xmlHttpObj;
    var randomnumber=Math.floor(Math.random()*10001)
    url +=  "&rand=" + randomnumber;

    xmlHttpObj = GetXmlHttpRequestObject();

    if (xmlHttpObj) {
        if ($('ajaxLoader'))
            $('ajaxLoader').setStyle('visibility', 'visible');
        xmlHttpObj.open("GET", url, true);
        
        if (f != null)
            xmlHttpObj.onreadystatechange = function(){
                if (xmlHttpObj.readyState == READYSTATE_COMPLETE)
                {
					f(xmlHttpObj);
				}
            };
        xmlHttpObj.send(null);
    }

}

function AddToOptionList(OptionList, OptionValue, OptionText) {
   // Add option to the bottom of the list
  
   OptionList[OptionList.length] = new Option(OptionText, OptionValue);
}

function clearCombo(combo)
{
	if (combo.type != 'text')
	{
		combo.options.length = 0;
	}
}