Get The Month Weeks in Drop-Down List

Hi all,

          I have a list with name "CompanyDetails". And it has some columns

              * Title, Description, Date, Company Name

              * Month & Year and day as calculated columns in the List

And in visual webpart I have a dropdown list. My task Is I need to fetch  all the weeks of current month and bind to dropdown-list on page load by setting default item as current week.

Can any one help me how can i do this.

Samar