I manage to solve the problem.
It is simple use the custom email address control.
Alternatively place the following javascript in normal textbox control.
// Validate the email address.
var
r = new RegExp("^[a-z0-9_\\-\\.]+\\@[a-z0-9_\\-\\.]+\\.[a-z]{2,3}$"); // Create a new Regular Expression Object.
// Set the regular expression to look for an email address in general form.
var
result = r.test(this.rawValue); // Test the rawValue of the current object to see
// if it fits the general form of an email address.
if
(result == true) // If it fits the general form,
true; // all is well.
else
// Otherwise,
false; // fail the validation.