IE8 - IFRAME causes refresh of entire page

Question

I have an uploader file based on IFRAME. It works fine with Firefox and Google Chrome but with Internet Explorer 8, when you send a file the entire page, is refreshed. Following my code:

JS:

  function test(){
     iframe = document.createElement("IFRAME");  
     iframe.name = "iframe_upload";
     iframe.id = "iframe_upload"; //some browsers target by id not name
     document.body.appendChild(iframe);
     document.getElementById("test").target = "iframe_upload";
  }

HTML:

<form id="test" method="post" target="iframe_upload" enctype="multipart/form-data" onsubmit="javascript:test()" action="test.php">
  <input name="image" type="file" /> 
  <input type="submit" value="Submit" />
</form>

Answer 1

Return from onsubmit action:

onsubmit="return test();"

and return false from function:

function test(){
   iframe = document.createElement("IFRAME");  
   iframe.name = "iframe_upload";
   iframe.id = "iframe_upload"; //some browsers target by id not name
   document.body.appendChild(iframe);
   document.getElementById("test").target = "iframe_upload";
   return false;
}