function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        ro = new XMLHttpRequest();
    }
    return ro;
}

var http = createRequestObject();

function showSearchBox(selectedtype) {

	var url = "search_box.php";
	var data = "type=" + selectedtype.value;

	http.open("POST", url, true);
	http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    http.send(data);
	http.onreadystatechange = handleResponse;

}

function handleResponse() {

  if (http.readyState == 4) {
 
	      results = http.responseText.split("---!---");
	      
			document.getElementById(results[0]).innerHTML = results[1];

	}
}