Simple JS Help

[Dentafrice1]

I need to pass a variable on through a URL in javascript

function createRequestObject(){
  var request_;
  var browser = navigator.appName;
  if(browser == "Microsoft Internet Explorer"){
    request_ = new ActiveXObject("Microsoft.XMLHTTP");
  }
  else
  {
    request_ = new XMLHttpRequest();
  }
  return request_;
}
var http = createRequestObject();
function getInfo(){
  http.open('get', 'test2.php?username='
    + document.forms[0].message.value);
  http.onreadystatechange = handleInfo;
  http.send(null);
}
function handleInfo(){
  if(http.readyState == 4){
    var response = http.responseText;
    test = 'http://imager.ffwbmarion.com/sample.php?text='+ document.forms[0].message.value;
    document.getElementById('image').innerHTML = test;
  
  }
}

Down there where it selects the div image. I need it to be

<img src=testurl> but I cant figure out how to put that variable test in an image tag.. any ideas?

[nets]

document.getElementById('image').src = 'foo';

[Dentafrice1]

but I need the innerHTML to be <img src='theurldefinedintest'>

[nets]

document.getElementById('image').innerHTML = '<img src="'+test+'" />';