function isValidEmailFunc(str) {
   return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
}


String.prototype.trim = function() {
    a = this.replace(/^\s+/, '');
    return a.replace(/\s+$/, '');
};

String.prototype.isValidEmail = function() {
    return isValidEmailFunc(this);
};

function handleError(asStr) {
    alert(asStr);
}
function checkFields() {
    var llZipLen;
    
    $('fname').value = $('fname').value.trim();
    $('lname').value = $('lname').value.trim();
    $('email').value = $('email').value.trim();
    $('Zip').value = $('Zip').value.trim();
    
    if ($('fname').value == '') {
      handleError('Please enter first name.');
      return false;
    }
    
    if ($('lname').value == '') {
      handleError('Please enter last name.');
      return false;
    }
    
    if ($('email').value == '') {
      handleError('Please enter email address.');
      return false;
    }
    
    if (!$('email').value.isValidEmail()) {
      handleError('Please enter a valid email address.');
      return false;
    }
    
    if ($('State').value.length != 2) {
      handleError('Please select State.');
      return false;
    }
    
    if ($('Zip').value == '') {
      handleError('Please enter Zip code.');
      return false;
    }
    
    llZipLen = $('zip').value.length;
    
    if (llZipLen != 5 && llZipLen != 9 && llZipLen != 10) {
      handleError('Please enter a valid Zip code.');
      return false;
    }
    
    return true;
}