// browser-friendly version to retrieve elements
function safeGetElemById(id) {

  var obj;

  if (document.getElementById)
    var obj = document.getElementById(id);
  else if(document.all)
    var obj = document.all[id];
  else if(document.layers)
    var obj = document.layers[id];
    
  return obj;
}

// validate form
function validate() {
  
  var inputArr = document.getElementsByTagName("input");
  var fname = safeGetElemById("fname");
  var email = safeGetElemById("email");
  var flag = 0;
  
  if(fname.value.length == 0) {
    alert("Please enter a first name");
    return false;
  }
  
  if(email.value.match(/^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/) == null) {
    alert("Please enter a valid email address");
    return false;
  }
  
  for(var i = 0; i < inputArr.length; i++) {
  
    if(inputArr[i].checked == true) {
      return true;
    }
  }
  alert("You must check at least one program or activity");
  return false;
}