site hover function review

javascript.js

// the function gets called inline via the onmouseover and onmouseout events like this
P7_MultiClass2('L3','show','nav_03','active_03')"

// essentially, the function is using the calling parameters to set set the classname for another item on the page
// since the classname they're adding is the "active_03", "active_04", etc., this is triggering the display of 
// the submenu when you hover the nav item.
function P7_MultiClass2() {
  var args=P7_MultiClass2.arguments;
  // so, args = ['L3','show','nav_03','active_03']
  if(document.getElementById) {
    for(var i=0; i<args.length; i+=2) {
      // so, this steps through from 0 to 2, at 4 it's out of the loop
      if(document.getElementById(args[i])!= null) {
        // so, it checks for an element
        // first, it looks for an element with id 'L3' (args[0])
        // second, it looks for an element with id 'nav_03' (args[2])
        if(document.p7setdown) {
          // here I'm lost - not sure what p7setdown is - I can't find it
          for(var k=0; k<p7dco.length-1; k+=2) {
            // also not sure what p7dco is, can't find it either
            if(args[i] == p7dco[k]) {
              args[i+1] = p7dco[k+1];
              break;
            }
          }
        }
        document.getElementById(args[i]).className=args[i+1];
      }
    }
  }
}

// so, reading this code, and not finding the p7 variables/elements anywhere else in the site, I'm led to believe
// that this is a modular function that someone pulled in from somewhere else, but that they aren't using the 
// functionality related to the p7 vars, which seems to be a method of overriding what comes in on the parms
// of the function call with some other default value, but it's not needed for the basic hover functionality

// it goes without saying that there is a much better/easier way to do this using jQuery.