About the difference between jsp page name = "username" and name = "username" is

　　We can look more closely, above the name attribute is equal to username, but really there is a gap or less the same, why do I say, because a second one more space than the first, in the jsp, I have encountered a case that two radio buttons with the same name locked, but the problem failed, after careful examination later found to have a radio button name more than one space, the core principle is not very clear, but may be more than a guess then a space, then in the jsp represents the different. Therefore, similar to the name attribute and other attributes of space must not exist at the time of writing.