This is a simple code for toggling password input fields into text fields and vice versa. You must provide a listener element, like a check box, and the inputs ID you want to toggle as 'passwordInputA, passwordInputB, ...'.

PasswordsVisible.js

function PasswordsVisible(listener, fields) {
	this.obscure = true;
	this.fields = fields;
	this.listener = $('#' + listener);
	this.length = 0;

	this.init();
}
PasswordsVisible.prototype = {
	init : function() {
		var me = this;

		me.fields = me.fields.split(', ');
		me.length = me.fields.length;
		me.listener.on('click', function() {
			me.toggle();
		});
	},
	toggle : function() {
		var me = this;
		var type = '';
		
		if (me.obscure) {
			me.obscure = false;
			type = 'text';
		} else {
			me.obscure = true;
			type = 'password';
		}
		
		for(var i = 0; i < me.length; i++) {
			$('input#' + me.fields[i]).attr('type', type);
		}
	}
};