//globals 
var first   	= "key_postcode";      // id of first SELECT 
var second  	= "straatnaam";      // id of second SELECT
var third		= "woonplaats";      // id of third SELECT
var global_id	= "";      			// global_id
// 
function sendRequest(url,params,HttpMethod) 
{ 
	// check if http method is defined, if not, set it to GET
    if(!HttpMethod) 
    {    
        HttpMethod="GET"; 
    } 
    
    // initialize request object 
    req=null; 
    if(window.XMLHttpRequest)
    {    
        req=new XMLHttpRequest; //mozilla/safari 
    } 
    else if(window.ActiveXObject)
    {    
        req=new ActiveXObject("Microsoft.XMLHTTP"); //internet explorer 
    } 

//define callback handler 
    if(req) 
    { 
        //    
        req.onreadystatechange=onReadyState;    
        req.open(HttpMethod,url,true);    
        req.setRequestHeader("Content-Type","application/x-www-form-urlencoded");    
        req.send(params); 
    } 
} 

function onReadyState() 
{ 
    // 
    var ready=req.readyState; 
    var data=null; 
    //

	if(ready==4)
    {      
        if(document.getElementById(first+global_id).value.length!="")
        {
            data=req.responseText;    
            var items = data.split(',');
			
			var childkey_straatnaam = document.getElementById(second+global_id); //create option       
			var woonplaats = document.getElementById(third+global_id);       
			childkey_straatnaam.value = items[0];   
			woonplaats.value = items[1];  
        }
    } 
}

// get model
function clicked_postcode(i) 
{ 
    global_id = i;

	var selected = document.getElementById(first+global_id).value;
	sendRequest('postcode/fetch_straatnaam.php?key_postcode='+selected);   
}