Code:
 	if(customer== ""){
		document.getElementById('customerInfo').innerHTML = "";
		return;
	}


In this code, Why is the RETURN there? It doesn't work without the return, and it doesn't matter if i put return false, or return true.. (full code underneath)

Code:
function toonKlant(klantnaam){
 	if(klantnaam == ""){
		document.getElementById('hint').innerHTML = "";
		return;
	}
	
	if(window.XMLHttpRequest){
		xmlhttp = new XMLHttpRequest();
	} else {
		xmlhttp = new ActiveXObject('Microsoft.XMLHTTP');
	}
	
	xmlhttp.onreadystatechange = function(){
		if(xmlhttp.readyState == 4 && xmlhttp.status == 200){
			document.getElementById("hint").innerHTML = xmlhttp.responseText;
		}
	}
	xmlhttp.open('GET','toonklant.php?name=', true);
	xmlhttp.send();
}