function checkuseradd() {
  var username = document.form.username.value;
  var password = document.form.password.value;
  
  if (username == '') {
  	alert ('You must enter a username.');
  	return false;
  } else if (password == '') {
  	alert ('You must enter a password.');
  	return false;
  } else
    
function checkimageadd() {
	var ext = document.form.image.value;
	ext = ext.substring(ext.length-3,ext.length);
  	ext = ext.toLowerCase();
 
	if (ext != 'jpg' && ext != 'gif') {
		alert ('Image is not a correct file extension. Please use supported formats:\n\n .jpg .gif');
		return false;
	} else {
		return true;
	}
}