// JavaScript Document

function validate(){     

    if (form.name.value=='') {
    alert("Please type your name.");
    form.name.focus();
    return false;
  }   
    if (form.telephone.value=='') {
    alert("Please type your telephone.");
    form.telephone.focus();
    return false;
  }   
    if (form.email.value=='') {
    alert("Please, type a valid email address.");
    form.email.focus();
    return false;
  }   
    if (form.comments.value=='') {
    alert("Please type a message.");
    form.comments.focus();
    return false;
  }   
    return true;
  }