function getCountries()
{
	
	var course_id=document.getElementById('course').options[document.getElementById('course').selectedIndex].value;
	//var city_id=document.getElementById('city').options[document.getElementById('city').selectedIndex].value;
	
	//document.getElementById("city_td").innerHTML='';
		
	country_xmlHttp=CountryGetXmlHttpObject()
	if (country_xmlHttp==null)
  	{
  		alert ("Your browser does not support AJAX!");
  		return;
  	} 
  
  		var url="../includes/ajax/get_countries.php";
		url=url+"?course_id="+course_id
		//url=url+"&city_id="+city_id
		url=url+"&sid="+Math.random();
		country_xmlHttp.onreadystatechange=CountryStateChanged;
		country_xmlHttp.open("GET",url,true);
		country_xmlHttp.send(null);
 }//function 


 
function CountryStateChanged() 
{ 
	if (country_xmlHttp.readyState==4)
	{ 
		var country_response=country_xmlHttp.responseText;
		if(country_response!=0)
		{
		//document.getElementById('course_div').style.visibility='visible';
		document.getElementById('country_td').innerHTML='';
		document.getElementById('country_td').innerHTML=country_response;		
		}
	}
}
 

function CountryGetXmlHttpObject()
{
	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;
}