function validate() {
var f = document.f;
var alerts = new Array(), i=0;
if(frozen) return; // because mozilla doesn't recognize disabled A elements
// validate form fields
if(bad(f.first_name) & bad(f.last_name)) alerts[i++] = "Please tell us your first and last name.";
else if(bad(f.first_name)) alerts[i++] = "Please tell us your first name.";
else if(bad(f.last_name)) alerts[i++] = "Please tell us your last name.";
if(bad(f.phone)) alerts[i++] = "Please give us a phone number we can reach you at.";
if(bad(f.email)) alerts[i++] = "Please enter your email address so we can reply.";
if(bad(f.subject)) alerts[i++] = "Please provide a subject for this email.";
if(blank(f['body'])) alerts[i++] = "You forgot to type a message.";
// display problem box if necessary
var oProblem = document.getElementById("problem");
var oUL = oProblem.childNodes[2];
oUL.innerHTML = ""; // clear alerts
if(alerts.length) { // if necessary, show alerts in problem box
for(i=0; i\n"; // add alerts
oProblem.style.display = "block"; // show problem box
oProblem.scrollIntoView();
return;
} else oProblem.style.display = "none"; // hide problem box
// the data is OK
goTo(document.f, 'contact_submit.php'); // submit the form
freeze(document.f); // prevent user from changing form data
return;
}