var iPath = '/images/nav/';
var iExt = 'gif';
var suffix = new Array('on', 'off');

function preLoad()
{
  if(document.images)
  {
    //alert("in");
    var argLen = arguments.length;
    for(var i = 0; i < argLen; i++)
    {
      var arg = arguments[i];
      var sufLen = suffix.length;
      for(j = 0; j < sufLen; j++)
      {
        var suf = suffix[j]
        self[arg + '_' + suf] = new Image();
        self[arg + '_' + suf].src = iPath + arg + '_' + suf + '.' + iExt;
      }
      //alert(i);
    }
  }
}

function rollOver(iName, iState)
{
  if(document.images && self[iName + '_' + iState])
  {
    //alert("in");
    document.images[iName].src = self[iName + '_' + iState].src;
  }
}