function check() {
  var ext = document.f.picture_file.value;
  
  var oas = new ActiveXObject("Scripting.FileSystemObject");

  var d = document.f.picture_file.value;

  var e = oas.getFile(d);

  var f = e.size;

  alert(f + "500000");
  
  if (ext.length < 5){
	alert('The length of the file name is too small assuming that the extension is at least 3 caracters.');
	document.f.picture_file.value = "";
    return false;
  }
  ext1 = ext.substring(ext.rindex("."),ext.length);
  ext1 = ext.toLowerCase();
  var ext2 = ext1.substring(ext.length-3,ext.length);
  if(ext1 != 'jpeg' && ext1 != 'jpg') {
    alert('You selected a .'+ext+
          ' file; please select a .jpg file instead!');
	document.f.picture_file.value = "";
    return false;
  }
  else
    return true;
}