Check selected words in the ListBox with Database Items

Question

Hi,
    I have created an silverlight application for that i use listbox for displaying a set of words or sentence for selecting a specific error words in that sentence, for that i use the database to check the selected words are match with that words in the database,
and then i have to display the next sentence by clicking the next button in the application, in that next question there are  also some words to be selected ,for that i have to give coding in that next button . can any one tell me how to connect the database in silverlight with WCF for matching the N Number of words in a sentence and coding for the next button click. Thank u in Advance.Its Urgent.Give me the Code.