Passing HashMap as POST parameter

If you would like to pass a hashmap as a parameter to a POST call in JavaScript, you need to use the dot notation and it will be interpreted as belonging to a hashmap. The code below loops through the properties of an object called 'options' and adds each one except for the toString() method to the POST parameter hashmap.
Declaration of options variable

var options = {
foo: 'blah',
boo: 'muah',
toString: function() {
return + ', ' +;

Inside AJAX call function

if (options != null) {
for (property in options) {
if (property != 'toString')
post_data['options.' + property] = options[property];

Using this code when you access the POST parameters on the server side, you can reference the 'options' POST parameter as a hashmap, i.e. options['foo'].