function notempty(edit,comment)
{
  flag=true;
  input=new String(edit.value);
  if (input.length==0)
  {
  	alert(comment);
    flag=false;
  }
  return(flag);

}

function isValidEmail(edit, comment) {
  str=edit.value;
  flag=(str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  if (!flag)
  {
    alert(comment);
  }
  return flag;
}

function newsLetter(email)
{
	if(notempty(email,'Please input email!') && isValidEmail(email, 'Email is not valid!')){
		xmlHttp=GetXmlHttpObject();
		if (xmlHttp==null)
			{
			alert ("Your browser does not support AJAX!");
			return;
			} 
		var url='/newsletters.php';
		url=url+'?newsletter_email='+email.value;
		
		xmlHttp.onreadystatechange=function()
		{
			if (xmlHttp.readyState==4)
			{ 			
			document.getElementById("news_error_box").innerHTML=xmlHttp.responseText;	
			document.getElementById("news_letter").value='Subscribe for newsletters';
			}
		}
		xmlHttp.open("GET",url,true);
		xmlHttp.send(null);
	}
}

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