function checkForm() {
  name = document.getElementById("myname").value;
  email = document.getElementById("myemail").value;
  trip = document.getElementById("mytrip").value;
 
  if (name == "") {
    hideAllErrors();
    document.getElementById("nameError").style.display = "inline";
    document.getElementById("myname").select();
    document.getElementById("myname").focus();
    return false;
  } else if (email.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) == -1) {
    hideAllErrors();
    document.getElementById("emailError").style.display = "inline";
    document.getElementById("myemail").select();
    document.getElementById("myemail").focus();
    return false;
  } else if (trip == "") {
    hideAllErrors();
    document.getElementById("tripError").style.display = "inline";
    return false;
  }
  return true;
}
 
function hideAllErrors() {
  document.getElementById("nameError").style.display = "none"
  document.getElementById("emailError").style.display = "none"
  document.getElementById("tripError").style.display = "none"
}