function validateForm(mainform) {
  if (mainform.name.value =="") 
  {
    alert("Please provide your name.");
    mainform.name.focus();
    return false;
  } 
  else if (mainform.company.value =="") 
  {
    alert("Please provide your company's name.");
    mainform.company.focus();
    return false;
  } 
  else if (mainform.email.value =="") 
  {
    alert("Please provide your email address.");
    mainform.email.focus();
    return false;
  } 
  else if (mainform.phone.value =="") 
  {
    alert("Please provide your phone number.");
    mainform.phone.focus();
    return false;
  } 
  else 
  {
    return true;
  }
}