Change home page Content with onchange of select box option

Hi everyone ,

In my new yii project, I am trying to do some experiments.But getting a bit confuse for the approach to complete this task.

Well, i need to change whole content of home page(A home page include widgets block.As i have divided a home page content in a widgets).And there is a City drop downbox on the home page.So when a user change a city from the drop down then a home page should be changed according to this city selected by user and that city would be selected in a drop down.

I was approaching to submit a form on the onchange event of the dropdownbox. and got the submitted city data in the $_GET parameter.And on the basis of $_GET parameters i am writing my widget blocks code.

But during this approach i got some problem.

1.) I can not maintain the city selected by user for the whole site while user is navigating to the other pages.But for that purpose i wrote a city data in the session and use in the component class. (Which is not a good Approach and this is what i do want to do.)

2.) After writing a value into a session when will i destroy these session variable. :(

Well this is what i have done yet so far and what kind of problems i have faced yet.

So, to all my friends. Anybody can suggest me some good ideas to complete this task or can help me out to fix the issues what i am facing now. :)

Thanks and regards ,