/* -----parse parameter in url----------- */
function getParameter(paramName) {
var searchString = window.location.search.substring(1);
var params = searchString.split("&");
for (i=0;i<params.length;i++) {
val = params[i].split("=");
if (val[0] == paramName) {
  return val[1];
}
}
return null;
}

function goYear() {
document.location.href="param.php?year=" + document.form.year.options[document.form.year.selectedIndex].value;
}

function goMake() {
var year=getParameter("year"); 
if (year){ 
document.location.href='param.php?year=' + year + '&make=' + document.form.make.options[document.form.make.selectedIndex].value;
} 
}



function doDirect(theField){
  window.location.href = theField;
}