Я монстр. Удалось!
function checkForm(){
var email = document.getElementById("email").value;
var totalItems = document.getElementById("totalItems")
var message = '<div class="alert alert-warning fade in">' +
'<button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>'+
'<strong>Incorrect Email'+
'</div>';
var pattern = /^([a-z0-9_\.-])+@[a-z0-9-]+\.([a-z]{2,4}\.)?[a-z]{2,4}$/i;
if(!pattern.test(email)){
document.getElementById("errorBlock").innerHTML = message;
}
else
document.getElementById("orderForm").submit();
}