var xmlHttp


function UpdatePage(page, variables){
  xmlHttpPage=GetXmlHttpObject();
  if (xmlHttpPage==null){
    alert ("Your browser does not support AJAX!");
    return;
  } 

  var pageName = variables.substr(5);
  document.newsletterForm.page.value = pageName;
  
  var tab_url = page + "?" + variables;  
  xmlHttpPage.onreadystatechange=PageChanged;
  xmlHttpPage.open("GET",tab_url,true);
  xmlHttpPage.send(null);
}

function PageChanged(){
  if(xmlHttpPage.readyState==4) {
    document.getElementById("ColumnCenter").innerHTML=xmlHttpPage.responseText;
  }
}





function GetXmlHttpObject(){  
  try{xmlHttp=new XMLHttpRequest();     // Firefox, Opera 8.0+, Safari   
  }catch (e){    
    try{xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");    // Internet Explorer     
    }catch (e){     
      xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");               
    }    
  } 
  
  return xmlHttp;
}