How to best send + symbol?

[mctrivia]

function getXMLHttp()
{
  var xmlHttp

  try
  {
    //Firefox, Opera 8.0+, Safari
    xmlHttp = new XMLHttpRequest();
  }
  catch(e)
  {
    //Internet Explorer
    try
    {
      xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch(e)
    {
      try
      {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch(e)
      {
        alert("Your browser does not support AJAX!")
        return false;
      }
    }
  }
  return xmlHttp;
}

function MakeRequest()  //$request1,$request2,...,$callback=null
{
  $request="av0=" + escape(arguments[0]);
  var xmlHttp = getXMLHttp();
  if (arguments.length > 1) {
    for ($i=1;$i<arguments.length-1;$i++) {
      $request=$request + "&av" + $i + "=" + escape(arguments[$i]);
    }
    if (arguments[arguments.length-1]==null) {
      xmlHttp.onreadystatechange = function () {};
    } else {
      eval("xmlHttp.onreadystatechange = " + "function () { if (xmlHttp.readyState == 4) {" + arguments[arguments.length-1] + "(xmlHttp.responseText);}};");
    }
  } else {
    xmlHttp.onreadystatechange = function () {};
  }
  xmlHttp.open("POST", "ajax", true);
  xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");         
  xmlHttp.send($request);
}

 

The previous code is my AJAX script.  I wrote it myself as a way to understand how it works and to deal with my sites strange structure.  It works except when I pass a value to it with a + symbol the php sees this as a space probably because i use escape(arguments[$i]) to deal with the issue of some other special characters being in the input.  Any ideas how to fix the script or process results in php so all characters can be passe?

[mctrivia]

problem solved.  use encodeURIComponent instead of escape.