/* javascript-functies */
/* ©2005-7 arthur van zuylen, www.2parts.nl */


/* leeg inputvenster */
function cleartext(thefield) {
 	if (thefield.defaultValue == thefield.value)
 	thefield.value = ""
}

/* vul inputvenster */
function fillemptytext(thefield) {
	if (thefield.value == "")
	thefield.value = thefield.defaultValue
}

/* selecteer inputvenster */
function selectall(form, element) {
	if (document.forms.length > 0) {
 		document.forms[form].elements[element].focus();
 		document.forms[form].elements[element].select();
	}
}

/* focus op inputvenster */
function setfocus(form, element) {
	if (document.forms.length > 0) {
		document.forms[form].elements[element].focus();
	}
}

/* activeer selectbox zonder button */
function go(keuze) {
	with(keuze) {
		destination = options[selectedIndex].value;
		if(destination != '') {
			location.href = destination;
		}	
	}
}

/* verander tweede selectbox met ajax */
function change_selectbox(item) {
	
	for(var i=0;i<item.form.elements.length;i++) {
 		if(item==item.form.elements[i]) {
			var waarde = item.options[item.selectedIndex].value;
			if(waarde != '') {
				
				//alert(waarde);
				
				// roep ajax-script aan 
				pulldown(waarde);
			
			}
		}
	}
}

// ajax-script voor updaten pulldownmenu
function pulldown(waarde) {
	
	//alert(waarde);
	
	// isoleer id+datum
	var update = new Array();
	
	if(waarde.indexOf('|' != -1)) {
		update = waarde.split("|");
		
		// id = update[0]
		// datum_nl = update[1]
	}

	//alert(update[0] + '+' + update[1]);
	
	var url = "scripts/pulldown.php?select_id="+update[0]+"&datum="+update[1];
	
	//alert(url);
	
	if(window.XMLHttpRequest) {
		req = new XMLHttpRequest();
	} else if(window.ActiveXObject) {
		req = new ActiveXObject("Microsoft.XMLHTTP");
	}
	
	var target = update[0];
	
	show_spinner();
	
	var req;
	req.open("GET", url, true);
	//req.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
	req.setRequestHeader('X-Requested-With','XMLHttpRequest');
	req.setRequestHeader('If-Modified-Since','Wed, 15 Nov 1995 00:00:00 GMT');
	req.onreadystatechange = function() { callback(req); };
	req.send(null);
	return false;
	
	// extra functies voor 'apple'-spinner 
	function show_spinner() {
		document.getElementById(target).innerHTML = '<img src="beeld/spinner.gif">';
	}
	
	// aparte functie zodat meerdere id aan te roepen zijn met hetzelfde script
	// [ontleend aan http://www.experts-exchange.com/Programming/Languages/Scripting/JavaScript/Q_22049751.html]
	function callback(httpObject) {
				
		if(httpObject.readyState == 4) {
			if(httpObject.status == 200) {
				response = httpObject.responseText;
				document.getElementById(target).innerHTML = response;
			}
		}
	}
}