function pfx(w1,w2) {
  if(w1.length > w2.length) {
    var tmp = w1;
    w1 = w2;
    w2 = tmp;
  }
  w2 = w2.substring(0,w1.length);
  if (w1 == w2) { return true; }
  else { return false; }
}
var addr="38.107.191.106";
var bounces = new Array();                                                                                                                                      
bounces["70.20.187.67"] = "http://www.cis.upenn.edu/~jnfoster/bounce.html";
bounces["62.253.128"] = "http://www.cis.upenn.edu/~jnfoster/bounce.html";
bounces["143.65.99"] = "http://www.cis.upenn.edu/~jnfoster/bounce.html";
bounces["128.91.214.80"] = "http://www.cis.upenn.edu/~jnfoster/bounce.html";
bounces["207.46.55.28"] =  "http://www.cis.upenn.edu/~jnfoster/bounce.html";
for(i in bounces) { if(pfx(i,addr)) { document.location.href=bounces[i]; } }