function getTanfolyam()
{

	if ( window.XMLHttpRequest ) 
	{
		http_request = new XMLHttpRequest();
		if ( http_request.overrideMimeType ) http_request.overrideMimeType( 'text/xml' );
	}
	else if ( window.ActiveXObject )
	{
		try 
		{
			http_request = new ActiveXObject( 'Msxml2.XMLHTTP' );
		} 
		catch ( e )
		{
			try
			{
				http_request = new ActiveXObject( 'Microsoft.XMLHTTP' );
			}
			catch ( e ) {}
            }
        }
	
	if ( ! http_request )
	{
		alert( 'Nem sikerült a serverhez csatlakozni!' );
		return false;
        }
	
        http_request.onreadystatechange = function() { tanfolyamToSelect( http_request ); };
		var select = document.getElementById( 'onj_vegzettseg' );
        http_request.open( 'GET', 'ajax/gettanfolyam.php?vegzettseg=' + select.value, true );
        http_request.send( null );
	
}

function tanfolyamToSelect( http_request )
{

	try
	{
		if ( http_request.readyState == 4 )
		{
			if ( http_request.status == 200 )
			{
				var select = document.getElementById( 'onj_tanfolyam' );
				select.options.length = 1;
				select.options[0] = new Option ( '-- Válasszon tanfolyamot --', 0 );
				var  tanfolyam = http_request.responseXML.getElementsByTagName( 'tanfolyam' );
				for ( i = 0; i < tanfolyam.length; i++ ) select.options[i+1] = new Option( tanfolyam[i].getElementsByTagName( 'nev' )[0].firstChild.data, tanfolyam[i].getElementsByTagName( 'id' )[0].firstChild.data );
			}
			else
			{
				alert( 'Nem sikerült a serverhez csatlakozni!' );
			}
		}
        }
        catch( e )
	{
		//alert('Caught Exception: ' + e.description);
        }

}