var linkRequest = null;

function initPage(){
    loadMainPage(1);
}

function loadMainPage(pageId){
    if(linkRequest == null){
        linkRequest = getXMLHTTPRequest();
		
        linkRequest.onreadystatechange = function(){
            switch(linkRequest.readyState){
                case 0:
                    break;
                case 1:
                    break;
                case 2:
                    break;
                case 3:
                    break;
                case 4:
                    document.getElementById("content").innerHTML = linkRequest.responseText;
                    break;
            }
        }
    }
	
    linkRequest.open("GET", "pages/loadPage.php?pageId=" + pageId, true, null, null);
    linkRequest.send(null);
}

function getXMLHTTPRequest(){
    var xmlHttp = null;
	
    try{
        // Mozilla, Opera, Safari sowie Internet Explorer (ab v7)
        xmlHttp = new XMLHttpRequest();
    } 
    catch(e){
        try{
            // MS Internet Explorer (ab v6)
            xmlHttp  = new ActiveXObject("Microsoft.XMLHTTP");
        } 
        catch(e){
            try{
                // MS Internet Explorer (ab v5)
                xmlHttp  = new ActiveXObject("Msxml2.XMLHTTP");
            } 
            catch(e){
                xmlHttp  = null;
            }
        }
    }
	
    return xmlHttp;
}