function buildArray() {
	var a = buildArray.arguments;
	for (i=0; i<a.length; i++) {
		this[i] = a[i];
	}
	this.length = a.length;
}

var urls1 = new buildArray("",
  "pr_bilstein.html",
  "pr_castrol.html",
  "pr_csc.html",
  "pr_eibach.html",
  "pr_lester.html");

function go(which, num) {
  n = which.selectedIndex;
  if (n != 0) {
    var url = eval("urls" + num + "[n]")
    location.href = url;
  }
}