View_messages "class"
I believe you are overcomplicating things. Declaring a prototype, will not make your code any more robust or even faster. I'm sure you know, but actually something like the code below will be easier to read, more effective and also faster.

/**
 *    View_message
 *    Object Model
 */ 
var ViewMessage = function(div) {
    this.div = document.getElementById(div); 

    this.messages = { 
        empty: 'Please complete all fields',
        empty_bm: 'Please enter both a title and url',
        name: 'Only letters or dashes for the name field',
        email: 'Please enter a valid email',
        same: 'Please make emails equal',
        taken: 'Sorry that email is taken',
        pass: 'Please enter a valid password, 6-40 characters',
        validate: 'Please contact &lt;a class="d" href="mailto:support@host.com"&gt;support&lt;/a&gt; to reset your password',
        url:  'Pleae enter a valid url'
    };

    this.display = function(type) {
        this.div.innerHTML = this.messages[type];

        return this;
    };

    return this;
};


Then two ways of doing this:

var view = new ViewMessage('divID');
    view.display('email');


OR

var view = new ViewMessage('divID').display('email');